AirTurn make a number of Bluetooth foot controllers that can be used by guitarists (or any musician) for a number of different applications. The first I heard of this device was when I spoke to Michael Dolce and Chris Kamzelas when they joined the band for first series of The Voice Australia, they explained how they were using a wireless foot controller to turn the sheet music on their iPads.
I wrongly assumed that these products were just for page turning applications but I have since found some interesting videos where guitarists are using the AirTurn pedals to control effects in iOS & Android apps. For instance here you can see the AirTurn BT-105 4-pedal controller being used with Positive Grid’s JamUp Pro XT for the iPad to turn pedals on and off in your chain. Another application is Loopy HD which is a looper that can be controlled by an AirTurn wireless foot controller like the BT-105. Check out this demo and just imagine the possibilities for guitarists.
For more information on AirTurn pedals and compatible apps check out http://www.airturn.com/