This cable allows you yo connect your guitar with headphones to your device. You can use the simple Voice Memo app that comes with the phone to record riffs or entire songs anywhere. Then you can instantly email your track to anyone. All apps become more powerful as well. Use the iPod tuner in a noisy environment like a club or record a tune on the 4-track recorder app.
I am seriously second guessing my choice of the Blackberry Tour as my smart phone these days….