Excellent

The only app youll need for learning the notes on the guitar neck (bass neck, etc.), and the notes on the treble and bass clef, and which notes on the guitar (bass...) correspond with which notes on the treble and bass clef. I stumbled along trying to learn to read music for years and never got very good results for my efforts, but this app makes it a piece of cake, and fun to boot!

Wally Flint about Fret Tester - Learn Notes