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.
Gowalla, the location aware social networking service, has announced the release of their first public API (our Gowalla API profile). This will help them keep up with other location-centric social services like Foursquare's new API.
I'vRead is a service for keeping track of what books you've read. Seems simple, but it can be rather useful for those of us obsessed with reading like myself. Its web site offers the service for free, and using it is already pretty simple. There isn't even another account to register for. All a user needs to do is add a specific tag, @ivread, to a Twitter post mentioning the book. It allows for some basic searches of the data on their website, but the I'vRead API is where the service really shines.