Agile Partners' iPhone guitar application, Guitar Toolkit, includes a high accuracy chromatic tuner with alternate tunings, over 260 chord diagrams, 1300-plus chord variations, a metronome with multiple time signatures, and tune-by-ear reference tones. There is support for bass (4- and 5-string) and 12-string guitar, as well as support for lefty players. Strummable chords and scales are available, too. Version 1.2.1 provides tuner support for the second-generation iPod Touch (a headset with microphone is required) as well as other improvements. GuitarToolkit Lite (without tuner) is available for the first-generation iPod Touch.
For more info, click to www.GuitarToolkit.com