Metronaut - An app to help you play classical music
Allo.io - Whiteboarding, documentation, and video chat in one place.
Transposr - A free and simple way to transpose your sheet music or MP3.
Butter - Butter is a newly launched chatting application that focuses more on the privacy of its users.
Flat for Education - The best way to teach music to your students
Draw.Chat - Anonymous real-time whiteboard with text and video chat.