diff --git a/.rubocop.yml b/.rubocop.yml
index 4eaad6ea..f893244b 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -111,11 +111,8 @@ Style/CaseEquality:
 Style/ClassAndModuleChildren:
   Enabled: true
 
-# Offense count: 577
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
 Style/StringLiterals:
-  Enabled: false
+  Enabled: true
 
 Style/TrailingBlankLines:
   Enabled: true
diff --git a/Guardfile b/Guardfile
index 43fd63b2..3f92b1a3 100644
--- a/Guardfile
+++ b/Guardfile
@@ -8,7 +8,7 @@ guard_opts = {
   cmd: 'spring rspec'
 }
 
-def model_specs       ; "spec/models"       end
+def model_specs       ; 'spec/models'       end
 
 def model_spec(model)
   "spec/models/#{model}_spec.rb"
diff --git a/app/controllers/admin/callforpapers_controller.rb b/app/controllers/admin/callforpapers_controller.rb
index b18d80de..650c9901 100644
--- a/app/controllers/admin/callforpapers_controller.rb
+++ b/app/controllers/admin/callforpapers_controller.rb
@@ -28,7 +28,7 @@ module Admin
       else
         redirect_to(admin_conference_callforpapers_path(
                     id: @conference.short_title),
-                    alert: "Updating call for papers failed. #{@cfp.errors.to_a.join(". ")}.")
+                    alert: "Updating call for papers failed. #{@cfp.errors.to_a.join('. ')}.")
       end
     end
 
@@ -44,7 +44,7 @@ module Admin
       else
         redirect_to(admin_conference_callforpapers_path(
                     id: @conference.short_title),
-                    alert: "Creating the call for papers failed. #{@cfp.errors.to_a.join(". ")}.")
+                    alert: "Creating the call for papers failed. #{@cfp.errors.to_a.join('. ')}.")
       end
     end
   end
diff --git a/app/controllers/admin/difficulty_levels_controller.rb b/app/controllers/admin/difficulty_levels_controller.rb
index cfab7528..b8cb674c 100644
--- a/app/controllers/admin/difficulty_levels_controller.rb
+++ b/app/controllers/admin/difficulty_levels_controller.rb
@@ -13,18 +13,18 @@ module Admin
           begin
             @conference.use_difficulty_levels = false
             @conference.save!
-            flash[:error] = "You cannot enable the usage of difficulty levels without having set any levels."
+            flash[:error] = 'You cannot enable the usage of difficulty levels without having set any levels.'
             redirect_to(admin_conference_difficulty_levels_path(conference_id: @conference.short_title))
           rescue ActiveRecord::RecordInvalid
-            flash[:error] = "Something went wrong. Difficulty Levels update failed."
+            flash[:error] = 'Something went wrong. Difficulty Levels update failed.'
             redirect_to(admin_conference_difficulty_levels_path(conference_id: @conference.short_title))
           end
         else
-          flash[:notice] = "Difficulty Levels were successfully updated."
+          flash[:notice] = 'Difficulty Levels were successfully updated.'
           redirect_to(admin_conference_difficulty_levels_path(conference_id: @conference.short_title))
         end
       else
-        flash[:error] = "Difficulty Levels update failed."
+        flash[:error] = 'Difficulty Levels update failed.'
         redirect_to(admin_conference_difficulty_levels_path(conference_id: @conference.short_title))
       end
     end
diff --git a/app/controllers/admin/questions_controller.rb b/app/controllers/admin/questions_controller.rb
index 08a17728..f001155e 100644
--- a/app/controllers/admin/questions_controller.rb
+++ b/app/controllers/admin/questions_controller.rb
@@ -33,7 +33,7 @@ module Admin
     # GET questions/1/edit
     def edit
       if @question.global
-        redirect_to(admin_conference_questions_path(conference_id: @conference.short_title), alert: "Sorry, you cannot edit global questions. Create a new one.")
+        redirect_to(admin_conference_questions_path(conference_id: @conference.short_title), alert: 'Sorry, you cannot edit global questions. Create a new one.')
       end
     end
 
@@ -73,13 +73,13 @@ module Admin
               flash[:notice] = "Deleted question: #{@question.title} and its answers: #{@question.answers.map {|a| a.title}.join ','}"
             end
           rescue ActiveRecord::RecordInvalid
-            flash[:error] = "Could not delete question."
+            flash[:error] = 'Could not delete question.'
           end
         else
-          flash[:error] = "You cannot delete global questions."
+          flash[:error] = 'You cannot delete global questions.'
         end
       else
-        flash[:error] = "You must be an admin to delete a question."
+        flash[:error] = 'You must be an admin to delete a question.'
       end
 
       @questions = Question.where(global: true).all | Question.where(conference_id: @conference.id)
diff --git a/app/controllers/admin/supporters_controller.rb b/app/controllers/admin/supporters_controller.rb
new file mode 100644
index 00000000..62a1b5a9
--- /dev/null
+++ b/app/controllers/admin/supporters_controller.rb
@@ -0,0 +1,19 @@
+module Admin
+  class SupportersController < Admin::BaseController
+    load_and_authorize_resource :conference, find_by: :short_title
+    load_and_authorize_resource through: :conference
+
+    def index
+      respond_to do |format|
+        format.html
+        format.json { render json: DatatableSupporters.new(@conference.supporter_registrations, view_context) }
+      end
+    end
+
+    def create
+      params[:supporter_registration][:conference_id] = @conference.id
+      SupporterRegistration.create!(params[:supporter_registration])
+      redirect_to(admin_conference_supporters_path(conference_id: @conference.short_title), notice: 'Supporter added')
+    end
+  end
+end
diff --git a/app/controllers/admin/volunteers_controller.rb b/app/controllers/admin/volunteers_controller.rb
index e6c53e6e..558b20cb 100644
--- a/app/controllers/admin/volunteers_controller.rb
+++ b/app/controllers/admin/volunteers_controller.rb
@@ -25,7 +25,7 @@ module Admin
     def update
       if can_manage_volunteers(@conference)
         if @conference.update_attributes(params[:conference])
-          redirect_to(admin_conference_volunteers_info_path(conference_id: params[:conference_id]), notice: "Volunteering options were successfully updated.")
+          redirect_to(admin_conference_volunteers_info_path(conference_id: params[:conference_id]), notice: 'Volunteering options were successfully updated.')
         else
           redirect_to(admin_conference_volunteers_info_path(conference_id: params[:conference_id]), alert: "Volunteering options update failed: #{@conference.errors.full_messages.join '. '}")
         end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 1e8d6cd1..e01a9d00 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -8,7 +8,7 @@ class ApplicationController < ActionController::Base
   check_authorization unless: :devise_controller?
 
   def store_location
-    session[:return_to] = request.fullpath if request.get? && controller_name != "user_sessions" && controller_name != "sessions"
+    session[:return_to] = request.fullpath if request.get? && controller_name != 'user_sessions' && controller_name != 'sessions'
   end
 
   def after_sign_in_path_for(resource)
@@ -49,7 +49,7 @@ class ApplicationController < ActionController::Base
   end
 
   rescue_from CanCan::AccessDenied do |exception|
-    Rails.logger.debug("Access denied!")
+    Rails.logger.debug('Access denied!')
     redirect_to root_path, alert: exception.message
   end
 
diff --git a/app/controllers/conference_controller.rb b/app/controllers/conference_controller.rb
index 488ec052..34f2adc6 100644
--- a/app/controllers/conference_controller.rb
+++ b/app/controllers/conference_controller.rb
@@ -9,14 +9,14 @@ class ConferenceController < ApplicationController
       subscription = Subscription.new(user_id: current_user.id, conference_id: conference.id)
       begin
         subscription.save!
-        flash[:success] = "You have been subscribed to receive Email Notifications from this Conference."
+        flash[:success] = 'You have been subscribed to receive Email Notifications from this Conference.'
         redirect_to root_path
       rescue ActiveRecord::RecordInvalid
         flash[:error] = subscription.errors.full_messages.to_sentence
         redirect_to root_path
       end
     else
-      flash[:notice] = "Already Subscribed"
+      flash[:notice] = 'Already Subscribed'
       redirect_to root_path
     end
   end
@@ -25,7 +25,7 @@ class ConferenceController < ApplicationController
     conference = Conference.find_by_short_title(params[:id])
     subscription = current_user.subscriptions.where(conference_id: conference.id).first
     if subscription.blank?
-      flash[:notice] = "Already Unsubscribed"
+      flash[:notice] = 'Already Unsubscribed'
       redirect_to root_path
     else
      begin
@@ -41,6 +41,6 @@ class ConferenceController < ApplicationController
 
   def gallery_photos
     @photos = @conference.photos
-    render "photos", formats: [:js]
+    render 'photos', formats: [:js]
   end
 end
diff --git a/app/controllers/event_attachments_controller.rb b/app/controllers/event_attachments_controller.rb
new file mode 100644
index 00000000..146e5dae
--- /dev/null
+++ b/app/controllers/event_attachments_controller.rb
@@ -0,0 +1,110 @@
+class EventAttachmentsController < ApplicationController
+  load_and_authorize_resource :conference, find_by: :short_title
+  load_and_authorize_resource :proposal, class: Event
+  load_and_authorize_resource :upload, class: EventAttachment, through: :proposal
+  before_filter :verify_user
+  skip_before_filter :verify_user, only: [:show]
+
+  def index
+    @uploads = @proposal.event_attachments
+    @uploads = @uploads.map{|upload| upload.to_jq_upload }
+
+    respond_to do |format|
+      format.html # index.html.erb
+      format.json { render json: @uploads.to_json}
+    end
+  end
+
+  def show
+    if @upload.public?
+      send_file @upload.attachment.path
+      return
+    end
+
+    if current_user.nil?
+      verify_user
+      return
+    end
+
+    if organizer_or_admin? || current_user == upload.event.submitter
+      send_file @upload.attachment.path
+    else
+      raise ActionController::RoutingError.new('Not Found')
+    end
+  end
+
+  def new
+    @upload = EventAttachment.new
+
+    respond_to do |format|
+      format.html # new.html.erb
+      format.json { render json: @upload }
+    end
+  end
+
+  def edit; end
+
+  def create
+    params[:event_attachment][:title] = params[:title][0]
+    params[:event_attachment][:public] = false
+    params[:event_attachment][:event_id] = params[:proposal_id]
+
+    if cannot? :create, EventAttachment
+      begin
+        current_user.events.find(params[:proposal_id])
+      rescue
+        # They certainly aren't allowed to attach a file to someone else's proposal
+        raise ActionController::RoutingError.new('Invalid proposal')
+      end
+    end
+
+    if params.has_key?(:public)
+      params[:event_attachment][:public] = true
+    end
+    @upload = EventAttachment.new(params[:event_attachment])
+
+    respond_to do |format|
+      if @upload.save
+        format.html do
+          render json: [@upload.to_jq_upload].to_json,
+                 content_type: 'text/html',
+                 layout: false
+        end
+        format.json do
+          render json: [@upload.to_jq_upload].to_json, status: :created,
+                 location: conference_proposal_event_attachment_path(@upload.event.conference.short_title, @upload.event, @upload)
+        end
+      else
+        format.html { render action: 'new' }
+        format.json { render json: @upload.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  def update
+    respond_to do |format|
+      if @upload.update_attributes(params[:upload])
+        format.html { redirect_to @upload, notice: 'Upload was successfully updated.' }
+        format.json { head :no_content }
+      else
+        format.html { render action: 'edit' }
+        format.json { render json: @upload.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  def destroy
+    if can? :destroy, @proposal
+      @upload = @proposal.event_attachments.find(params[:id])
+    end
+
+    @upload.destroy if !@upload.nil?
+
+    respond_to do |format|
+
+      format.html { redirect_back_or_to conference_proposal_index_path(@conference.short_title), notice: "Deleted successfully attachment '#{@upload.title}' for proposal '#{@proposal.title}'" }
+
+      format.json { head :no_content }
+    end
+  end
+end
diff --git a/app/controllers/home_controller.rb b/app/controllers/home_controller.rb
index 8da4883f..8a53dfcb 100644
--- a/app/controllers/home_controller.rb
+++ b/app/controllers/home_controller.rb
@@ -4,7 +4,7 @@ class HomeController < ApplicationController
 
   def index
     @today = Date.current
-    @current = Conference.where("end_date >= ?", @today).order("start_date ASC")
+    @current = Conference.where('end_date >= ?', @today).order('start_date ASC')
   end
 
   def respond_to_options
diff --git a/app/controllers/proposal_controller.rb b/app/controllers/proposal_controller.rb
index 10c2a94f..76bdded6 100644
--- a/app/controllers/proposal_controller.rb
+++ b/app/controllers/proposal_controller.rb
@@ -76,7 +76,7 @@ class ProposalController < ApplicationController
     end
 
     redirect_to(conference_proposal_index_path(conference_id: @conference.short_title),
-                notice: "Proposal was successfully updated.")
+                notice: 'Proposal was successfully updated.')
   end
 
   def destroy
@@ -92,7 +92,7 @@ class ProposalController < ApplicationController
 
     @event.save(validate: false)
     redirect_to(conference_proposal_index_path(conference_id: @conference.short_title),
-                notice: "Proposal was successfully withdrawn.")
+                notice: 'Proposal was successfully withdrawn.')
   end
 
   def confirm
diff --git a/app/controllers/schedule_controller.rb b/app/controllers/schedule_controller.rb
index 85aa6d19..efdc65c8 100644
--- a/app/controllers/schedule_controller.rb
+++ b/app/controllers/schedule_controller.rb
@@ -1,6 +1,6 @@
 class ScheduleController < ApplicationController
   authorize_resource class: false
-  layout "application"
+  layout 'application'
 
   def index
     @conference = Conference.
@@ -11,9 +11,9 @@ class ScheduleController < ApplicationController
     @dates = @conference.start_date..@conference.end_date
 
     if @dates == Date.current
-      @today = Date.current.strftime("%Y-%m-%d")
+      @today = Date.current.strftime('%Y-%m-%d')
     else
-      @today = @conference.start_date.strftime("%Y-%m-%d")
+      @today = @conference.start_date.strftime('%Y-%m-%d')
     end
   end
 end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 8047d250..788e9b96 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -92,17 +92,17 @@ module ApplicationHelper
 
   def getdatetime(registration, field)
     if registration.send(field.to_sym).kind_of?(String)
-      DateTime.parse(registration.send(field.to_sym)).strftime("%d %b %H:%M") if registration.send(field.to_sym)
+      DateTime.parse(registration.send(field.to_sym)).strftime('%d %b %H:%M') if registration.send(field.to_sym)
     else
-      registration.send(field.to_sym).strftime("%d %b %H:%M") if registration.send(field.to_sym)
+      registration.send(field.to_sym).strftime('%d %b %H:%M') if registration.send(field.to_sym)
     end
   end
 
   def getdate(var)
     if var.kind_of?(String)
-      DateTime.parse(var).strftime("%a, %d %b")
+      DateTime.parse(var).strftime('%a, %d %b')
     else
-      var.strftime("%a, %d %b")
+      var.strftime('%a, %d %b')
     end
   end
 
@@ -122,24 +122,24 @@ module ApplicationHelper
   end
 
   def pre_registered(event)
-    @conference.events.joins(:registrations).where("events.id = ?", event.id)
+    @conference.events.joins(:registrations).where('events.id = ?', event.id)
   end
 
   def add_association_link(association_name, form_builder, div_class, html_options = {})
-    link_to_add_association "Add " + association_name.to_s.singularize, form_builder, div_class, html_options.merge(class: "assoc btn btn-success")
+    link_to_add_association 'Add ' + association_name.to_s.singularize, form_builder, div_class, html_options.merge(class: 'assoc btn btn-success')
   end
 
   def remove_association_link(association_name, form_builder)
-    link_to_remove_association("Remove " + association_name.to_s.singularize, form_builder, class: "assoc btn btn-danger") + tag(:hr)
+    link_to_remove_association('Remove ' + association_name.to_s.singularize, form_builder, class: 'assoc btn btn-danger') + tag(:hr)
   end
 
   def dynamic_association(association_name, title, form_builder, options = {})
-    render "shared/dynamic_association", association_name: association_name, title: title, f: form_builder, hint: options[:hint]
+    render 'shared/dynamic_association', association_name: association_name, title: title, f: form_builder, hint: options[:hint]
   end
 
   # Same as redirect_to(:back) if there is a valid HTTP referer, otherwise redirect_to()
   def redirect_back_or_to(options = {}, response_status = {})
-    if request.env["HTTP_REFERER"]
+    if request.env['HTTP_REFERER']
       redirect_to(:back)
     else
       redirect_to(options, response_status)
@@ -148,7 +148,7 @@ module ApplicationHelper
 
   # TODO Output better html
   def format_comments(comment, padding = 0)
-    result = ""
+    result = ''
     result += "<div style='padding-left:#{padding}px'>"
     result += "<div class='well'>"
     result += "<b>#{comment.user.name}</b> <i>#{comment.created_at}</i><br><br>"
@@ -160,12 +160,12 @@ module ApplicationHelper
     result += "<input name='authenticity_token' type='hidden' value='#{form_authenticity_token}' />"
     result += "<textarea name='comment'></textarea>"
     result += "<button class='btn btn-primary pull-right' name='button' type='submit'>Add Reply</button>"
-    result += "</form></div></div>"
-    result += "</div>"
+    result += '</form></div></div>'
+    result += '</div>'
     #result += edit_admin_conference_event_path(@conference.short_title, @event)
     comment.children.each do |child|
       result += format_comments(child, 50)
-      result += "</div>"
+      result += '</div>'
     end
 
     result
@@ -181,7 +181,7 @@ module ApplicationHelper
     markdown.render(text).html_safe
   end
 
-  def markdown_hint(text="")
+  def markdown_hint(text='')
     markdown("#{text} Please look at #{link_to '**Markdown Syntax**', 'https://daringfireball.net/projects/markdown/syntax', target: '_blank'} to format your text")
   end
 
diff --git a/app/helpers/proposal_helper.rb b/app/helpers/proposal_helper.rb
index 567b2c1f..f5b565fc 100644
--- a/app/helpers/proposal_helper.rb
+++ b/app/helpers/proposal_helper.rb
@@ -1,6 +1,6 @@
 module ProposalHelper
   def generate_abstract_length_js(conference)
-    str = ""
+    str = ''
     conference.event_types.map do |t|
       str += "if ($('select option:selected').text() == '#{t.title}') {\n"
       str += "str = '#{t.maximum_abstract_length}';\n"
diff --git a/app/helpers/registration_helper.rb b/app/helpers/registration_helper.rb
new file mode 100644
index 00000000..824ee1bb
--- /dev/null
+++ b/app/helpers/registration_helper.rb
@@ -0,0 +1,14 @@
+module RegistrationHelper
+  def generate_supporter_level_js(conference)
+    str = ''
+    conference.supporter_levels.map do |t|
+      next if t.url.empty?
+
+      str += "if ($('#registration_supporter_registration_attributes_supporter_level_id option:selected').text() == '#{t.title}') {\n"
+      str += "console.log('#{t.title}');\n"
+      str += "str = 'If you have a confirmation or registration code, enter it here.  Otherwise, you can purchase a <i>#{t.title}</i> ticket <a href=\"#{t.url}\" target=_new>here</a>, if you need to.';\n"
+      str += "}\n\n"
+    end.join("\n")
+    str
+  end
+end
diff --git a/app/mailers/mailbot.rb b/app/mailers/mailbot.rb
index 381b77bb..9cf89b88 100644
--- a/app/mailers/mailbot.rb
+++ b/app/mailers/mailbot.rb
@@ -1,5 +1,5 @@
 class Mailbot < ActionMailer::Base
-  default from: "no-reply@example.com"
+  default from: 'no-reply@example.com'
 
   def registration_mail(conference, person)
     build_email(conference,
diff --git a/app/models/ahoy/event.rb b/app/models/ahoy/event.rb
index 7599143a..a70e7e41 100644
--- a/app/models/ahoy/event.rb
+++ b/app/models/ahoy/event.rb
@@ -1,6 +1,6 @@
 module Ahoy
   class Event < ActiveRecord::Base
-    self.table_name = "ahoy_events"
+    self.table_name = 'ahoy_events'
 
     belongs_to :visit
     belongs_to :user
diff --git a/app/models/contact.rb b/app/models/contact.rb
index a4e28035..6efa8db0 100644
--- a/app/models/contact.rb
+++ b/app/models/contact.rb
@@ -4,7 +4,7 @@ class Contact < ActiveRecord::Base
 
   validates :conference, presence: true
   # Conferences only have one contact
-  validates :conference_id, uniqueness: {message: "has already contact details"}
+  validates :conference_id, uniqueness: {message: 'has already contact details'}
 
   validates :facebook, :twitter, :googleplus, :instagram,
             format: URI::regexp(%w(http https)), allow_blank: true
diff --git a/app/models/datatable.rb b/app/models/datatable.rb
index 4ba59673..03ec9038 100644
--- a/app/models/datatable.rb
+++ b/app/models/datatable.rb
@@ -79,7 +79,7 @@ class Datatable
       sort_by << "#{sort_column(colnum)} #{sort_direction(colnum)}"
       colnum += 1
     end
-    sort_by.join(", ")
+    sort_by.join(', ')
   end
 
   def sorted? index=0
@@ -93,6 +93,6 @@ class Datatable
 
   def sort_direction index=0
     index = "sSortDir_#{index}"
-    params[index] == "desc" ? "desc" : "asc"
+    params[index] == 'desc' ? 'desc' : 'asc'
   end
 end
diff --git a/app/models/event_attachment.rb b/app/models/event_attachment.rb
new file mode 100644
index 00000000..1fb3a1ee
--- /dev/null
+++ b/app/models/event_attachment.rb
@@ -0,0 +1,26 @@
+class EventAttachment < ActiveRecord::Base
+  has_paper_trail
+
+  belongs_to :event
+  attr_accessible :public, :attachment, :event_id, :title
+
+  has_attached_file :attachment, path: ':rails_root/storage/:rails_env/attachments/:id/:style/:basename.:extension'
+  include Rails.application.routes.url_helpers
+
+  def to_jq_upload
+    {
+        'name' => read_attribute(:attachment_file_name),
+        'size' => read_attribute(:attachment_file_size),
+        'title' => read_attribute(:title),
+        'public' => read_attribute(:public),
+        #"url" => attachment.url(:original),
+        'url' => conference_proposal_event_attachment_path(self.event.conference.short_title, self.event_id, self.id),
+        'delete_url' => conference_proposal_event_attachment_path(self.event.conference.short_title, self.event_id, self.id),
+        'delete_type' => 'DELETE'
+    }
+  end
+  #:path => ":rails_root/public/system/:attachment/:id/:style/:filename",
+  #    :url => "/system/:attachment/:id/:style/:filename"
+
+  #has_paper_trail :meta => {:associated_id => :event_id, :associated_type => "Event"}
+end
diff --git a/app/models/photo.rb b/app/models/photo.rb
index c7871db5..94be8716 100644
--- a/app/models/photo.rb
+++ b/app/models/photo.rb
@@ -3,7 +3,7 @@ class Photo < ActiveRecord::Base
   belongs_to :conference
   validates_presence_of :picture
   has_attached_file :picture,
-                    styles: { thumb: "100x100>", large: "300x300>", banner: "600x300>" }
+                    styles: { thumb: '100x100>', large: '300x300>', banner: '600x300>' }
 
   validates_attachment_content_type :picture,
                                     content_type: [/jpg/, /jpeg/, /png/, /gif/],
diff --git a/app/models/visit.rb b/app/models/visit.rb
index 6bb47fed..4ae9bb97 100644
--- a/app/models/visit.rb
+++ b/app/models/visit.rb
@@ -1,4 +1,4 @@
 class Visit < ActiveRecord::Base
-  has_many :ahoy_events, class_name: "Ahoy::Event"
+  has_many :ahoy_events, class_name: 'Ahoy::Event'
   belongs_to :user
 end
diff --git a/config/application.rb b/config/application.rb
index a9790016..43872169 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -36,7 +36,7 @@ module Osem
     # config.i18n.default_locale = :de
 
     # Configure the default encoding used in templates for Ruby 1.9.
-    config.encoding = "utf-8"
+    config.encoding = 'utf-8'
 
     # Configure sensitive parameters which will be filtered from the log file.
     config.filter_parameters += [:password]
diff --git a/config/environment.rb b/config/environment.rb
index bcd18b20..0e52b624 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -2,7 +2,7 @@
 require File.expand_path('../application', __FILE__)
 
 # Load the configuration file
-path = Rails.root.join("config", "config.yml")
+path = Rails.root.join('config', 'config.yml')
 begin
   CONFIG = YAML.load_file(path)[Rails.env]
 rescue
diff --git a/config/environments/test.rb b/config/environments/test.rb
index df75cb36..05845254 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -9,7 +9,7 @@ Osem::Application.configure do
 
   # Configure static asset server for tests with Cache-Control for performance
   config.serve_static_assets = true
-  config.static_cache_control = "public, max-age=3600"
+  config.static_cache_control = 'public, max-age=3600'
 
   # Do not eager load code on boot.
   config.eager_load = false
diff --git a/config/initializers/formtastic.rb b/config/initializers/formtastic.rb
index b676d4a0..29962539 100644
--- a/config/initializers/formtastic.rb
+++ b/config/initializers/formtastic.rb
@@ -22,7 +22,7 @@ Formtastic::FormBuilder.include_blank_for_select_by_default = false
 # '<abbr title="required">*</abbr>'. In other words, if you configure formtastic.required
 # in your locale, it will replace the abbr title properly. But if you don't want to use
 # abbr tag, you can simply give a string as below
-Formtastic::FormBuilder.required_string = "(required)"
+Formtastic::FormBuilder.required_string = '(required)'
 
 # Set the string that will be appended to the labels/fieldsets which are optional
 # Defaults to an empty string ("") and also accepts procs (see required_string above)
diff --git a/config/initializers/time_formats.rb b/config/initializers/time_formats.rb
index 437e1646..41eeb416 100644
--- a/config/initializers/time_formats.rb
+++ b/config/initializers/time_formats.rb
@@ -1 +1 @@
-Time::DATE_FORMATS[:db_without_seconds] = "%Y-%m-%d %H:%M"
+Time::DATE_FORMATS[:db_without_seconds] = '%Y-%m-%d %H:%M'
diff --git a/config/routes.rb b/config/routes.rb
index 3d3b98f3..d3d1366f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -69,7 +69,7 @@ Osem::Application.routes.draw do
         end
       end
 
-      patch "/questions/update_conference" => "questions#update_conference"
+      patch '/questions/update_conference' => 'questions#update_conference'
       resources :questions
 
       resources :events do
@@ -91,7 +91,7 @@ Osem::Application.routes.draw do
   resources :conference, only: [:show] do
     resources :proposal do
       resources :commercials, except: [:show, :index]
-      resources :event_attachment, controller: "event_attachments"
+      resources :event_attachment, controller: 'event_attachments'
       member do
         patch '/confirm' => 'proposal#confirm'
         patch '/restart' => 'proposal#restart'
@@ -103,13 +103,13 @@ Osem::Application.routes.draw do
     resources :ticket_purchases, only: [:create, :destroy]
 
     resource :schedule, only: [] do
-      get "/" => "schedule#index"
+      get '/' => 'schedule#index'
     end
 
     member do
-      get "gallery_photos"
-      patch "subscription" => "conference#subscribe"
-      delete "subscription" => "conference#unsubscribe"
+      get 'gallery_photos'
+      patch 'subscription' => 'conference#subscribe'
+      delete 'subscription' => 'conference#unsubscribe'
     end
   end
 
@@ -129,7 +129,7 @@ Osem::Application.routes.draw do
     end
   end
 
-  get "/admin" => redirect("/admin/conference")
+  get '/admin' => redirect('/admin/conference')
 
   root to: 'home#index', via: [:get, :options]
 end
diff --git a/db/migrate/20121223110942_devise_create_users.rb b/db/migrate/20121223110942_devise_create_users.rb
index aa694e16..60cc97dc 100644
--- a/db/migrate/20121223110942_devise_create_users.rb
+++ b/db/migrate/20121223110942_devise_create_users.rb
@@ -2,8 +2,8 @@ class DeviseCreateUsers < ActiveRecord::Migration
   def up
     create_table(:users) do |t|
       ## Database authenticatable
-      t.string :email,              null: false, default: ""
-      t.string :encrypted_password, null: false, default: ""
+      t.string :email,              null: false, default: ''
+      t.string :encrypted_password, null: false, default: ''
 
       ## Recoverable
       t.string   :reset_password_token
diff --git a/db/migrate/20121223115106_create_people_table.rb b/db/migrate/20121223115106_create_people_table.rb
index f378afaa..75563b7d 100644
--- a/db/migrate/20121223115106_create_people_table.rb
+++ b/db/migrate/20121223115106_create_people_table.rb
@@ -2,10 +2,10 @@ class CreatePeopleTable < ActiveRecord::Migration
   def up
     create_table :people do |t|
       t.string :guid, null: false
-      t.string :first_name, default: ""
-      t.string :last_name, default: ""
-      t.string :public_name, default: ""
-      t.string :company, default: ""
+      t.string :first_name, default: ''
+      t.string :last_name, default: ''
+      t.string :public_name, default: ''
+      t.string :company, default: ''
       t.string :email, null: false
       t.boolean :email_public
       t.string :avatar_file_name
diff --git a/db/migrate/20121223115125_create_tracks_table.rb b/db/migrate/20121223115125_create_tracks_table.rb
index 58d50fda..5680c476 100644
--- a/db/migrate/20121223115125_create_tracks_table.rb
+++ b/db/migrate/20121223115125_create_tracks_table.rb
@@ -5,7 +5,7 @@ class CreateTracksTable < ActiveRecord::Migration
       t.references :conference
       t.string :name, null: false
       t.text :description
-      t.string :color, default: "#ffffff"
+      t.string :color, default: '#ffffff'
 
       t.timestamps
     end
diff --git a/db/migrate/20121223115135_create_events_table.rb b/db/migrate/20121223115135_create_events_table.rb
index a0c9fac0..56f14f36 100644
--- a/db/migrate/20121223115135_create_events_table.rb
+++ b/db/migrate/20121223115135_create_events_table.rb
@@ -7,8 +7,8 @@ class CreateEventsTable < ActiveRecord::Migration
       t.string :title, null: false
       t.string :subtitle
       t.integer :time_slots
-      t.string :state, null: false, default: "new"
-      t.string :progress, null: false, default: "new"
+      t.string :state, null: false, default: 'new'
+      t.string :progress, null: false, default: 'new'
       t.string :language
       t.datetime :start_time
       t.text :abstract
diff --git a/db/migrate/20121223122307_create_event_people_table.rb b/db/migrate/20121223122307_create_event_people_table.rb
index 3459b433..27e32a44 100644
--- a/db/migrate/20121223122307_create_event_people_table.rb
+++ b/db/migrate/20121223122307_create_event_people_table.rb
@@ -4,7 +4,7 @@ class CreateEventPeopleTable < ActiveRecord::Migration
       t.references :proposal
       t.references :person
       t.references :event
-      t.string :event_role, null: false, default: "participant"
+      t.string :event_role, null: false, default: 'participant'
       t.string :comment
 
       t.timestamps
diff --git a/db/migrate/20130104142209_create_comments.rb b/db/migrate/20130104142209_create_comments.rb
index 23abf7f6..b9c9ce79 100644
--- a/db/migrate/20130104142209_create_comments.rb
+++ b/db/migrate/20130104142209_create_comments.rb
@@ -1,7 +1,7 @@
 class CreateComments < ActiveRecord::Migration
   def self.up
     create_table :comments do |t|
-      t.string :title, limit: 50, default: ""
+      t.string :title, limit: 50, default: ''
       t.text :comment
       t.references :commentable, polymorphic: true
       t.references :user
diff --git a/db/migrate/20140212172244_create_difficulty_levels.rb b/db/migrate/20140212172244_create_difficulty_levels.rb
index dd5be4d0..bdd9547c 100644
--- a/db/migrate/20140212172244_create_difficulty_levels.rb
+++ b/db/migrate/20140212172244_create_difficulty_levels.rb
@@ -4,7 +4,7 @@ class CreateDifficultyLevels < ActiveRecord::Migration
       t.references :conference
       t.string :title
       t.text :description
-      t.string :color, default: "#ffffff"
+      t.string :color, default: '#ffffff'
 
       t.timestamps
     end
diff --git a/db/seeds.rb b/db/seeds.rb
index 5d8d6774..286cec69 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -14,9 +14,9 @@ user.skip_confirmation!
 user.save!
 
 # Questions
-qtype_yesno = QuestionType.create(title: "Yes/No")
-QuestionType.create(title: "Single Choice")
-QuestionType.create(title: "Multiple Choice")
+qtype_yesno = QuestionType.create(title: 'Yes/No')
+QuestionType.create(title: 'Single Choice')
+QuestionType.create(title: 'Multiple Choice')
 
 answer_yes = Answer.create(title: 'Yes')
 answer_no = Answer.create(title: 'No')
diff --git a/spec/factories/email_settings.rb b/spec/factories/email_settings.rb
index fb009931..4fc7764e 100644
--- a/spec/factories/email_settings.rb
+++ b/spec/factories/email_settings.rb
@@ -15,13 +15,13 @@ FactoryGirl.define do
     updated_conference_registration_dates_subject 'Conference registration dates have been updated'
     updated_conference_registration_dates_template 'Sample Conference\n New Dates: January 17 - 21 2014'
     send_on_venue_update true
-    venue_update_subject "Venue has been updated"
-    venue_update_template "Venue has been Updated to Sample Location"
+    venue_update_subject 'Venue has been updated'
+    venue_update_template 'Venue has been Updated to Sample Location'
     registration_subject 'Lorem Ipsum Dolsum'
     registration_email_template 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit'
-    call_for_papers_dates_updates_subject "Call for Papers dates have been updated"
-    call_for_papers_dates_updates_template "Please checkout the new updates to submit your proposal for Sample Conference"
-    call_for_papers_schedule_public_subject "Sample Conference Cfp schedule is Public"
-    call_for_papers_schedule_public_template "Call for Papers schedule is Public.Checkout the link"
+    call_for_papers_dates_updates_subject 'Call for Papers dates have been updated'
+    call_for_papers_dates_updates_template 'Please checkout the new updates to submit your proposal for Sample Conference'
+    call_for_papers_schedule_public_subject 'Sample Conference Cfp schedule is Public'
+    call_for_papers_schedule_public_template 'Call for Papers schedule is Public.Checkout the link'
   end
 end
diff --git a/spec/features/event_types_spec.rb b/spec/features/event_types_spec.rb
index a71aacfa..425aab75 100644
--- a/spec/features/event_types_spec.rb
+++ b/spec/features/event_types_spec.rb
@@ -44,7 +44,7 @@ feature EventType do
                  value).to eq('300')
 
       # Remove event type
-      within("div.nested-fields:nth-of-type(3)") do
+      within('div.nested-fields:nth-of-type(3)') do
 	click_link 'Remove event_type'
       end
       expect(page.all('div.nested-fields').count == 2).to be true
diff --git a/spec/features/omniauth_spec.rb b/spec/features/omniauth_spec.rb
index 3d343a8f..93ccd4a4 100644
--- a/spec/features/omniauth_spec.rb
+++ b/spec/features/omniauth_spec.rb
@@ -15,7 +15,7 @@ feature Openid do
       visit '/accounts/sign_in'
 
       mock_auth_new_user
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
       expect(flash).to eq('test-1@gmail.com signed in successfully with google')
@@ -30,7 +30,7 @@ feature Openid do
       visit '/accounts/sign_in'
 
       mock_auth_existing_user_participant
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
       expect(flash).to eq('test-participant-1@google.com signed in successfully with google')
@@ -42,7 +42,7 @@ feature Openid do
       OmniAuth.config.mock_auth[:google] = :invalid_credentials
       visit '/accounts/sign_in'
       expect(page.has_content?('or sign in using')).to be true
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
 
@@ -60,7 +60,7 @@ feature Openid do
       visit '/accounts/edit'
 
       mock_auth_new_user
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
       expect(flash).to eq('test-participant-1@google.com signed in successfully with google')
@@ -77,7 +77,7 @@ feature Openid do
       visit '/accounts/sign_in'
 
       mock_auth_existing_user_participant
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
       expect(flash).to eq('test-participant-1@google.com signed in successfully with google')
@@ -90,7 +90,7 @@ feature Openid do
       visit '/accounts/edit'
 
       mock_auth_new_user
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-google'
       end
       expect(flash).to eq('test-participant-1@google.com signed in successfully with google')
@@ -106,7 +106,7 @@ feature Openid do
 
       visit '/accounts/sign_in'
       mock_auth_new_user_fb
-      within("#openidlinks") do
+      within('#openidlinks') do
         click_link 'omniauth-facebook'
       end
       expect(flash).to eq('test-participant-1@google.com signed in successfully with facebook')
diff --git a/spec/features/photo_spec.rb b/spec/features/photo_spec.rb
index 9f9a94c0..b803eaeb 100644
--- a/spec/features/photo_spec.rb
+++ b/spec/features/photo_spec.rb
@@ -56,7 +56,7 @@ feature Photo do
       click_button 'Save Photo'
 
       expect(flash).
-          to eq("A error prohibited this Photo from being saved: Picture content type is invalid. Picture is invalid.")
+          to eq('A error prohibited this Photo from being saved: Picture content type is invalid. Picture is invalid.')
       expect(Photo.count).to eq(expected_count)
     end
   end
diff --git a/spec/support/save_feature_failures.rb b/spec/support/save_feature_failures.rb
index 8ff680cd..4cfb68d4 100644
--- a/spec/support/save_feature_failures.rb
+++ b/spec/support/save_feature_failures.rb
@@ -3,9 +3,9 @@
 RSpec.configure do |config|
   config.after(:each, type: :feature) do
     ename = RSpec.current_example.full_description
-    ename = ename.gsub " ", "_"
+    ename = ename.gsub ' ', '_'
     ename.downcase!
-    ename = ename + ".html"
+    ename = ename + '.html'
     if RSpec.current_example.exception.present?
       save_page(ename)
     else
diff --git a/spec/views/admin/conference/roles.html.haml_spec.rb b/spec/views/admin/conference/roles.html.haml_spec.rb
index 0223cf4c..cce0bef4 100644
--- a/spec/views/admin/conference/roles.html.haml_spec.rb
+++ b/spec/views/admin/conference/roles.html.haml_spec.rb
@@ -16,11 +16,11 @@ describe 'admin/conference/roles' do
     expect(rendered).to include("Add role 'Organizer' to user:")
     expect(rendered).to include('Add role')
     expect(rendered).to include('Users with role Organizer')
-    expect(rendered).to have_selector("table thead th:nth-of-type(1)", text: 'ID')
-    expect(rendered).to have_selector("table thead th:nth-of-type(2)", text: 'Name')
-    expect(rendered).to have_selector("table thead th:nth-of-type(3)", text: 'Email')
-    expect(rendered).to have_selector("table tbody tr:nth-of-type(1) td:nth-of-type(1)", text: organizer.id)
-    expect(rendered).to have_selector("table tbody tr:nth-of-type(1) td:nth-of-type(2)", text: 'test name')
-    expect(rendered).to have_selector("table tbody tr:nth-of-type(1) td:nth-of-type(3)", text: 'test@email.com')
+    expect(rendered).to have_selector('table thead th:nth-of-type(1)', text: 'ID')
+    expect(rendered).to have_selector('table thead th:nth-of-type(2)', text: 'Name')
+    expect(rendered).to have_selector('table thead th:nth-of-type(3)', text: 'Email')
+    expect(rendered).to have_selector('table tbody tr:nth-of-type(1) td:nth-of-type(1)', text: organizer.id)
+    expect(rendered).to have_selector('table tbody tr:nth-of-type(1) td:nth-of-type(2)', text: 'test name')
+    expect(rendered).to have_selector('table tbody tr:nth-of-type(1) td:nth-of-type(3)', text: 'test@email.com')
   end
 end
diff --git a/spec/views/admin/emails/index.html.haml_spec.rb b/spec/views/admin/emails/index.html.haml_spec.rb
index 44fd435c..89c3c394 100644
--- a/spec/views/admin/emails/index.html.haml_spec.rb
+++ b/spec/views/admin/emails/index.html.haml_spec.rb
@@ -18,15 +18,15 @@ describe 'admin/emails/index' do
         to include('Conference dates have been updated')
     expect(rendered).
         to include('Conference registration dates have been updated')
-    expect(rendered).to include("Venue has been updated")
-    expect(rendered).to include("Venue has been Updated to Sample Location")
+    expect(rendered).to include('Venue has been updated')
+    expect(rendered).to include('Venue has been Updated to Sample Location')
     expect(rendered).
-        to include("Call for Papers dates have been updated")
+        to include('Call for Papers dates have been updated')
     expect(rendered).
-        to include("Please checkout the new updates to submit your proposal for Sample Conference")
+        to include('Please checkout the new updates to submit your proposal for Sample Conference')
     expect(rendered).
-        to include("Sample Conference Cfp schedule is Public")
+        to include('Sample Conference Cfp schedule is Public')
     expect(rendered).
-        to include("Call for Papers schedule is Public.Checkout the link")
+        to include('Call for Papers schedule is Public.Checkout the link')
   end
 end
diff --git a/spec/views/home/index.html.haml_spec.rb b/spec/views/home/index.html.haml_spec.rb
index 5c258854..2beff825 100644
--- a/spec/views/home/index.html.haml_spec.rb
+++ b/spec/views/home/index.html.haml_spec.rb
@@ -1,10 +1,10 @@
 require 'spec_helper'
 
 describe 'home/index' do
-  it "renders _conference partial for each conference" do
-    allow(view).to receive(:date_string).and_return("January 17 - 21 2014")
+  it 'renders _conference partial for each conference' do
+    allow(view).to receive(:date_string).and_return('January 17 - 21 2014')
     assign(:current, [create(:conference), create(:conference)])
     render
-    expect(view).to render_template(partial: "_conference_details", count: 2)
+    expect(view).to render_template(partial: '_conference_details', count: 2)
   end
 end