very simple modular synth, iPhone only, but a nice idea..
Design your own instrument by wiring up simple modules. Included are three kinds of oscillators (sine wave, square wave, and sawtooth wave), a noise generator, and modules for combining and modifying signals. Dabble in techniques like additive synthesis and frequency modulation just by choosing different arrangements and wirings.
that video has been removed by the developer himself, so .. don’t know how it feels like, yet.