I sure looked at Apple docs, but mostly tutorials on the web like on raywenderlich.com (http://www.raywenderlich.com/42699/spritekit-tutorial-for-beginners http

I sure looked at Apple docs, but mostly tutorials on the web like on raywenderlich.com (http://www.raywenderlich.com/42699/spritekit-tutorial-for-beginners http://www.raywenderlich.com/42699/spritekit-tutorial-for-be...) and StackOverflow when needed of course :) But it's pretty cool, particularly for physics based games, makes things a lot easier. Of course one downside of using that is if you want to port it for Android.