This SDK is a Braintree Drop-In SDK for Android that allows you to accept card and alternative payments for Android applications. Braintree provides services for the collection of credit card and PayPal payments programmatically.
Windows Azure, the mobile back end as a service platform, has added custom APIs, Git, NPM, Android Push Notifications, along with a free SQL DB. As Scott Guthrie, who builds for Microsoft, demonstrates on his "Scottgu blog," the creation of custom APIs is extremely simple. Here's the first shot at the start of building an API that works with a to do list.