This App depends on the Recurly Client Library which can be installed as a gem.
gem install recurly --source=http://gemcutter.org
The Recurly Ruby Client App requires an API key to connect. Please see the Recurly Ruby client documentation for more all the options for specifying your API credentials.
The demo requires you to create a plan with a plan_code of 'test' in your Recurly Site's configuration or edit the TEST_PLAN_CODE in config/environment.rb
Please see the Recurly API for more information.