PASY02 (App Store link) is a new synthesizer based on a physical simulation. It retails for $0.99.

Description:

You can enjoy the sound visually with PASY02. Swing the net on the screen to control the sound.?If you pull the net, it waves under tension and the sound changes.

The net tention parameter settings are configurable.?You can choose waveform from sine, triangle, square and sawtooth wave. This application carries out physical operation. If you feel your iPhone is running slowly, try “flight mode”.

Features:

• synthesizer using physical simulation
• easy control
• configurable settings