CodeSignal - CodeSignal is the leading assessment platform for technical hiring.
Flowkey - The easiest way to learn piano with your iPhone or iPad
coderpad - Collaborative code editor with in-browser, real-time execution. Conduct programming phone screens like a boss.
Yousician - Learn to play music at home, at your own pace
CodeInterview.io - CodeInterview is a live coding interview tool for developers.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.