Tonestone built an app powered by Umajin for creating amazing music quickly.

Here is a great article on The Verge about Tonestone []

ToneStone is a music production app from the people behind Guitar Hero and Left 4 Dead. They want making music to be an easy, social experience

ToneStone is a musical creativity platform for everyone. Their interactive tools help you express yourself through music.

Create — Simple but powerful tools help you start making and sharing music in seconds.

Play — Game-like experiences get you into the creative flow and level up your skills.

Collaborate — Jam with friends in real-time, remix songs, and find fellow collaborators.