FL Studio Mobile - Create & save multi-track music projects on a smartphone
WaveShop - Open source audio editor
Splice Beat Maker - Make and share beats in your browser
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
Type Drummer - Drum by typing
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.