ChordHelper - ChordHelper is a web app that helps musicians of any level make chord progressions from scratch, without having to know any music theory.
ChordPic - Create beautiful guitar chord diagrams
ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Strike a Chord - Master the piano with this inventive new app 🎹
Simply Piano - Fast and fun way to learn piano
Scale Heaven - Browse and play any scale/chord, chord progression.