They will have an xbox one application that allows for full rebinds that takes place on the controller. It can store 2 different binding modes at the same time so you can easily switch between them within the flip of the switch and it happens transparently to the console. In their video they showan example of bindings for driving the warthog and then a different one for run and gun.
Yah, the binds are stored on the controller as well, so you can switch back and forth by flipping a switch. You don't need an app to switch bindings on the fly.