Late last year I mentioned a UIView category that made interesting use of CATransform3D allowing you to create the Mac OS X genie animation effect on an iOS UIView.
Here’s a library from Håvard Fossli called AGGeometryKit that provides a large number of useful utility functions making it easier to perform visual tricks using CATransform3D such as the aforementioned Genie effect.
This is one that you’ll need to play with yourself – but here’s a video demonstrating the library in action:
You can find AGGeometryKit on Github here.
Sample code is included. A very fun library to play with that you can use to make some unique animations.