Play the Guitar in GarageBand for iPhone - Apple Support (IE)
Fusion Guitar: Built-in amp and dock turns your iPhone into a roadie - CNET
COVER CHITARRA ELETTRICA per iPhone 3g/3gs 4/4s 5/5s/c 6/6s Plus iPod Touch 4/5/6 iPod nano 7 - covermania
Amazon.com: IK Multimedia iRig 2 Portable Guitar Audio Interface, Lightweight Audio Adapter for iPhone, iPad and Android Smartphones and Tablets, with Instrument Input and Headphone/amplfiier Outs : Musical Instruments