The Quickblox Android SDK by Quickblox offers a transition guide of versions along with references to run samples on Android Studio and Eclipse. Push notifications, simple Android custom objects, and simple Android chat are some of the examples available with images and code.
Three months after its initial launch, much-talked-about data portability service Gnip has released version 2.0 of its API, as well as the first glimpse of a business model. As we covered back in March, Gnip's goal is to "connect Data Consumers to Data Publishers in a low-latency, highly-scalable standards-based way." Gnip is a sort of proxy that makes data from diverse Publishers--services like Delicious or Twitter, which create activity content--available in a unified format, and notifies Consumers--like FriendFeed or Plaxo--via a push interface when new data is available. The new version of the API adds full data delivery, XMPP support, and advanced data filtering.