Sinatra app.rb fix for jacobbednarz (original gist: https://gist.github.com/00279c2749e202a82d6d).

app.rb

require 'sinatra/base'

class App < Sinatra::Base
  before do 
    @images = [
      { title: "matrix", url: "http://i0.kym-cdn.com/entries/icons/original/000/009/889/Morpheus2.jpg" },
      { title: "google", url: "http://i0.kym-cdn.com/news_feeds/icons/original/000/006/501/google-search.jpg" },
      { title: "skywalking", url: "http://i2.kym-cdn.com/photos/images/newsfeed/000/295/090/9de.jpg" }
    ]
  end
  
  get '/images' do
    @images
  end
 
  get '/images/:index' do
    @images[params[:index].to_i]
  end
end