Swatches - A fun and accurate color picker for the real world
Simply Piano - Fast and fun way to learn piano
ColorSnapper - The missing color picker for Mac.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.
Sketch Palettes - Sketch plugin to save and load colors into the color picker
Yousician - Learn to play music at home, at your own pace