iOS 7.0 has introduced a new feature called UIKit Dynamics. It allows the developer to define different forces and constraints (gravity, collision, attachments, arbitrary forces, spring, etc.) between UI elements (buttons, labels, table cells, etc.) and it contains a physics engine that animates these elements based on the forces and constraints. For example Game Center bubbles are implemented with the help of UIKit Dynamics.
Do you know any design guidelines, patterns or examples on how to design a cool dynamic UI with UIKit Dynamics?