Piano Melody Free - Piano Melody app allows you to listen to your favorite songs from a vast library of more than 1000 songs of different eras and genres.
UltimateGuitar.com - Learn how to play your favourite songs on guitar or ukulele
GuitarFX - GuitarFX is an application which is designed to create powerful and attractive guitar tone along with stunning base effects.
Guitar-Effects Alternatives - Guitar-Effects Alternatives is a digital amplifier and pedalboard that allows the guitarist to tune his instrument with his favorite tone.
ChordU - Extracts chords from any song, integrated YouTube.
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.