Porting a mobile app from one platform to another can be painful and challenging. The PortKit site lists the iOS 7 and 6 Cocoa elements alongside the Android 4+ equivalents, making it easier to identify the one you need if you're porting an app.
Each of the elements is linked to the relevant official documentation from Apple or Google, making this a really useful site to bookmark. The page, created by Brisbane-based web development shop Kintek, also offers some general app development hints and tips. Well worth checking out.