Robert Tubb has released The Wablet app, a physics based synthesiser and noise toy.
An animated mesh of springs can be vibrated with the fingers. The Mesh’s displacement around a path on this mesh is read as an audio waveform, and hence your gestures are turned into sound.
Complex evolving drones, chiptunes bleeps or full on noise can be produced, and beautiful undulating patterns created.
The physical properties of the mesh can be changed using the sliders, new sound-paths can be drawn onto the Mesh and the App comes with a Max/MSP patch for wireless MIDI control and more in depth adjustable parameters.
The Wablet is available to purchase for 0.89 EUR. Note: the app is currently not available in the US because of a patent on the underlying algorithm.
More information: The Wablet