ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.
muted.io - A magical collection of interactive music theory tools & visual reference pages for musicians and music producers
Noizio - Feeling that the noise of the big city is too much for you to bear?
ChordPic - Create beautiful guitar chord diagrams
zenmix.io - Ambient background sound generator