Memo.ai - Simple and elegant notes app on your Mac
SoundGrail - SoundGrail Music App designed for pianists, guitarists, and DJs.
Music Memos by Apple - An app to capture your song ideas
Figure - Propellerhead creates world-class software products and services that inspire music makers and provide the foundation for a worldwide creative musical community.
ikes - Capture & manage ideas in one place
keezy - A colorful soundboard. Play with music.