I've been trying to internalise the 3D APIs for a while, but not having this thing as my main focus makes it really hard.
Perhaps having things out, no matter how simple and silly they are, would help put some steam in my engine.
So here we go: https://github.com/arithma/ios3dball
It's quite simple, and the ball is drawn using a simple shader that allows seeing the rolling of the ball.
You'd need to close the app and open it again in order to reset the balls position.