Circuit Synth is a very simple and fun modular synthesizer for the iPhone. It allows you to hook up to six modules up in any order. The interface is very easy and friendly and even people not familiar with synthesis might have some fun with it and may even learn a thing or two. The offered modules are basic – no filters, just standard oscillators and modifiers. See video below.
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.
Developer: Michael Daines
See also Jasuto – a more in depth modular synthesizer.