Created by Agoston Nagy, SoundBow is a free sound instrument for Android devices which allows you to create melodies by drawing curves on the screen. Your curves are be remembered and played back continuously. Each time your ever-looping gesture hits a string, a sound is produced.
SoundBow is built with Processing (with native Android functions) and the sounds are handled by the free visual patching language Pure Data (using libPd for Android ).
Reusable source code & HTML 5 version (based on the mighty processingjs and the html5 audio tag) is coming soon.
If you are on iOS/Mac/Windows, see also SoundyThingie