Absolute Software '''''r Sidekick

If you want to use your Smartphone alongside your acoustic, electric or classical guitar, the Castiv Guitar Sidekick could prove useful. This grip is designed to hold any Smartphone or portable media player on your guitar so that you can use your guitar apps or watch YouTube lessons hands-free. Once it's affixed, you can use apps for video lessons, following lyrics, teleprompting, audio recording, a virtual metronome, tuning and more.