rails_angular_seo (rubygems):  rails_angular_seo allows you to make your single-page apps (Backbone, Angular, etc) built on Rails SEO-friendly. It works by injecting a small rack middleware that will render pages as plain html, when the requester is one of the most common crawlers/bots out there (Google, Yahoo Baidu and Bing) 
Keywords: angular|angularjs|rack-middleware|rails|rubygem|seo