Rebound framework for spring animations.
Rebound is a spring animation framework designed using physics.
It is open sourced by Facebook for android ,iOS ,web.
I have experienced the rebound animation in one of my application. It is very cool and easy to integrate in your application with in seconds.
Rebound is not only a general purpose physics engine it also uses spring dynamics to create animations.
To get started, visit the link http://facebook.github.io/rebound/