AVAnimator is an iOS library that makes it easy to implement non-trivial animated/video content in iOS.
See the project homepage for more information and example xcode projects:
http://www.modejong.com/AVAnimator/
This is an Open Source project, it is free as in "liberty" but that does not mean it is free as in "free beer". The specific goal of this project is to provide a professional library that can be incorporated into real iOS apps. Please take a moment to understand the dual license and how legal use of software is important.
http://www.modejong.com/AVAnimator/license.html
Example iOS projects: