Guitaroid - Listen to Guitaroid | SoundCloud is an audio platform that lets you listen to what you love and share the sounds you create.
UltimateGuitar.com - Learn how to play your favourite songs on guitar or ukulele
AudioKit Hey Metronome - Visit the post for more.
Guitaa.com - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.
Open Metronome - Open Metronome, a Free Open Source Metronome for Windows Mobile and Pocket PC.
ChordU - Extracts chords from any song, integrated YouTube.