This app is a companion to the post at hackernotes.io/data-behavior. It is a Ruby on Rails app with no dependencies beyond what is indicated in the Gemfile. To run it, simply execute:
$ bundle install
And...
$ bin/rake db:migrate
And...
$ bin/rake db:seed
And...
$ bin/rails server
The server will listen on its default port, 3000, and you can find the app at http://localhost:3000.