iPhysics is a physics engine for iPhone, which slowly turns out to develop into a game.

Changes:

Joints! Both on levels and player-made. Just tap on a shape or on the background to create. Double tap on background for the usual small ball.
Shape deletion! Double tap on a shape to delete it.
One extra Crayon Physics level, with joints.
Lots of new options for level makers
And a few levelpacks on the repository.

http://www.iphone.r4m0n.net/?p=17