The biggest challenge you'll face before you can start rocking out is positioning your iOS device. You want the screen and the front-facing camera pointed toward you. Whenever you setup GhostGuitar anew, the app requires that you re-configure it for a moment by giving it time to identify your hands, so that it can separate them from whatever background is present.

It's at this point that you're ready to bring on the funk. Your iOS device shows you, with a large guitar superimposed over you. GhostGuitars detects the placement of each of your hands; one handles strumming, and the other can trigger one of four virtual frets to choose the chord. (You can strum a fifth chord by strumming without selecting a fret.)

Were that all the app could do, it would be fun. But GhostGuitar packs in a surprising amount of power. First, you can pick your instrument (choose between an acoustic guitar and three electric models); they all sound good. You can also change the current key, and scroll through two dozen options for chord patterns (major, minor, blues, and the like). Even better, you can enter an advanced mode to set your own chord patterns, and save your favorites.

You can configure a variety of effects pedals for your guitar, too, adding chorus, vibrato, echo, and more. GhostGuitar smartly includes an option to sample your current guitar sound without switching back to the app's main view.

If you miss the full band experience, GhostGuitar has got you covered with a full ghost band. You can enable an automatic bass and guitar accompaniment and enable your device's built-in microphone; you configure the tempo, the drum type, the mike effect settings, and the virtual instruments play right along with you.