The Twitter Cocoa Objective-C SDK by Nathaniel Symer allows developers to integrate the Twitter API into their applications built with Cocoa, an Objective-C framework. This SDK can be found on CocoaPods.
Keek, social video network, recently announced the release of the Keek API. Alongside the API launch, Keek established a developer portal that includes tools and resources to assist developers in integrating Keek with third party applications. The Keek API grants developers access to public keeks (i.e. 36 second video updates), search, user profiles, klusters, and more.
Created in 2006, Big Art Mob's original purpose was to accompany the Channel 4 show, 'Big Art Project'; the goal being to create the UK's first comprehensive map of street art. The site is now being re-launched along with iPhone and iPad applications, inviting users to upload and map public art anywhere in the world.
Microsoft has released a suite of tools to integrate its popular Messenger client into your website. Called Messenger Connect, the new API embeds a Windows Live Messenger chat window on your site, which enables visitors to share links, collaborate, or just stay connected to friends.