ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Pianu - Learn to play the piano in your browser.
7Pad Scales and chords - Music instrument and assistant for playing scales and chords.
Flowkey - The easiest way to learn piano with your iPhone or iPad
Scales-Chords - Free online music tools featuring a searchable chord database and chord charts.
Joytunes - Learn music through mobile games