A simple and clean to implement login to facebook-ios-sdk using Blocks.
A framework to implement publishing videos to YouTube, Vimeo, Facebook and Flickr.
ShareKit provides drop-in share features for all iOS apps supporting the most popular social platforms such as Facebook, Twitter, Delicious and many more.
Three20 is a collection of iPhone UI classes derived from the Facebook iPhone app, and developed by Facebook. It currently includes a photo viewer, message composer, Web image views, Internet-aware table view controllers, better text fields, HTTP disk cache, and URL-based Navigation.