BeatStars - BeatStars is a social music marketplace & distribution co.
muted.io - A magical collection of interactive music theory tools & visual reference pages for musicians and music producers
Songtree - Songtree is an amazing mobile application that helps you to record music, rap songs, piano, synth, guitar, and vocals.
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.
Music Speed Changer (Classic) - Music Speed Changer (Classic) is an amazing mobile app that enables you to adjust the pitch and tempo of your music to make it slower or faster through sound touch processor.
Scale Heaven - Browse and play any scale/chord, chord progression.