Twitter4J is an unofficial Java library for the Twitter API. It is Android Platform ready as long as developers are using Java 5 or later. Integration can be done easily by including the Java dependencies in the developers pom.xml
Tangler, an online network of discussion forums, recently announced their new API. The Tangler service takes traditional discussion forums to a new level, by allowing anyone to easily set up a discussion forum that can grow to include hundreds of topics and thousands of users.
Instagram made API news today with new comment features, and a major upgrade. The Instagram Platform API has upgraded to Facebook's Graph API. This allows greater flexibility to access Instagram data from third party tools. Instagram commented that the API will be available to all developers soon.