Sale has ended but you can still get this app.
Download NoisePad Now
NoisePad

Official Description

NoisePad is a generative art application where you can create messed up graphics and sounds just by swiping your finger. It's pretty hard to explain, so just give it a try. The app has a bunch of settings to change the graphics and sounds. It's based on algorithmically generated noise, requires no permissions and is a small download.