1)   Guitar & Drum Trainer 2.3
Learn to play your favorite music on any instrument. Slow down music, create loops, pitch shift, filter frequencies with 16 band EQ and low pass filter, use volume FX to play over-top of songs, save song configurations, count in to songs. Guitar

 2)   JamoramaGuitar 2.7
Play Sensational Guitar With Jamorama ! Who Wants To Discover The Astonishing, Step-By-Step Secrets Of How To Play Guitar Like The Eagles, Eric Clapton, Jimi Hendrix, Red Hot Chilli Peppers, Nirvana, Bob Marley, Eddie Van Halen, Bruce Springsteen ?

 3)   ChordSMART 2
An invaluable reference tool for guitar players of any level. ChordSMART shows chords in any key in several tunings, and even shows you optional open strings.