The SpilGames Android SDK by SpilGames allows to integrate games into mobile applications that developers can monetize according to location. Requisites include Google Analytics API Key, App ID, and token.
There is something to be said for simplicity, especially when it comes to applications that leverage web APIs for mobile devices. Enter Sparrow, an application for the iPhone, that serves as a good example of how a few web APIs can be elegantly implemented for use on a mobile device.
There are a number of factors coming together to fuel the growth of APIs. Without a doubt, one is the corresponding growth of mobile devices and the distribution of services across multiple platforms. An API is often required to create one native mobile application and becomes incredibly important when supporting many devices. Sometimes these private APIs are made public, sometimes they aren't.