The official PlayFab C# SDK by PlayFab calls the PlayFab REST API to access game backend services. Features include analytics, player accounts, and virtual goods. TLS v1.1 is needed to connect to the Playfab service.
Recent reports and Android open source documentation indicate an Android Game SDK for Unity is in the works. Neither Google nor Unity has made announcements regarding the project; however, the move is a natural step for both Google and Unity given the current mobile device and gaming environment.
Gowalla's rocky couple of years ended with a talent acquisition by Facebook of the former location-sharing app. Left in the dust were developers using the Gowalla API, including Ben Dodson and his field notes app for Gowalla. Dodson's latest creation is a Gowalla-inspired app that focuses just on the gaming elements rather than check-ins. And because Dodson remembers struggling with Gowalla's early API, the WallaBee API is available from the start. In fact, before the start.