Grid is an open source visual synthesiser application designed for rhythmic, melodic, or textural applications. An exploration in frequency of sound and how it may be visualised. Developer description:

But has joy gone blind? No; there are primary colors in sound. There are primitives to sound, to the psychological constituents of sound; though there is a one to one correspondence between frequency and the reals, frequency is a property rather than a depiction of palpable tone. In this sense, the algorithm used is structurally formative rather than exhaustively descriptive of the sounds produced.

You can download the code (xcode project) here.

You may also enjoy PASY02 [iPhone]

Platform: iPhone
Version: 1.0
Cost: $3.99
Developer: Kin

UPDATE 19.02.2010: 5 promocodes up for grabs! Leave a comment below and we’ll pick winners by random later today.

Thanks Kin!