There are all sorts of apps for musicians on a bunch of different mobile phones like the iPhone and others. A company called CASTIV has unveiled a new accessory for musicians that like to use apps like metronomes and others while they practice their musical instrument.
The new accessory is called the Guitar Sidekick. It is made to mount to the neck of a guitar and hold a lot of different smartphone models so you can use the apps while you play. The device will work with just about any phone from the iPhone to Android devices, Blackberry, and even the PSP and iPod touch.