This unofficial Twitter Ruby gem is in its 5th version, and is heavily supported with documentation and code examples. Twitter Ruby Gem allows users to follow a user, retrieve a user name, fetch a timeline of tweets by a user, and many other functions. In this version of the gem, Twitter Streaming API is also experimentally supported.
With a domain like map.pr, you'd think this would be another link shortener. Instead, it uses the Foursquare API to give you a great way to visualize popular places on FourSquare. And, if you're following the World Cup, you can also use Mappr to find spots frequented by fellow fans.
Facebook this week introduced two major sets of developer tools for interacting with its various services. The company released a new software development kit for Apple's Swift programming language, and added lots of new features to its Graph API 2.7. Both toolsets are available in preview form.