Springs'nThings app for iPhone and iPad

Springs ‘n Things - Version 1.5
Both Physics and Fun

Springs and Things is an entertaining demonstration application and educational display for the iPhone/iPad. It simulates the dynamics of up to ten springs connected to a moveable ball. Touch, drag and release the ball to see it bounce around. The length and stiffness of the springs can be individually adjusted. One of the springs can be transformed into a fixed spring or a pendulum. The ball can be made to respond to the tilting and shaking motions of the iPad. The motion of the ball can be perpetual or it can be slowed by resistance as if it were moving in air or water.

Bounces forever
0-10 springs
Air, water, vacuum viscosity or any value in between
Turn gravity on or off - adjust gravity - shake and tilt sensitive
Real computer simulation accurate to 1%
Adjustable mass and spring resistance

Screen shots below:
1) 10 springs
2) a pendulum
3) modify mass screen with a large ball and 3 springs
4) modify spring screen with 3 springs
5) clear screen with a fixed spring and 9 additional springs