The Twitter Kit for iOS, supported by Twitter as part of the Fabric developer suite, helps developers create iOS applications that integrate various Twitter functionalities. The SDK can be used to implement easy Twitter login, composing tweets, displaying tweets, and authentication all from a 3rd party application. The iOS Twitter Kit includes "Login" for standard login, "Twitter API," for iOS driven API requests, "Tweet Views," for displaying a user's Twitter stream, "Tweet Compose," for composing and posting new tweets, and "Digits," a new way that users can verify with Twitter via their mobile phone number over SMS-based authentication.
After four months, Facebook is set to open its timeline actions to developers this week, according to AllThingsD. The feature is an addition to the Facebook Graph API that allows developers to assign verbs for actions users perform within applications. For example, how users now "like" things, they'll also be able to "read" articles, "play" games and "listen" to music. I would expect many, many actions to be submitted to Facebook for approval, especially related to game-specific acts. It's too early to tell how closely the social network will watch its pending list of actions, though there's a clear approval process.