Free Cellphone-based AutoPilot?

I've been following the development of Avare, the free open source aviation app for Android. Recently, some AddOn apps have been released, allowing Avare to interface with devices external to the Android device (GPS and ADSB receivers, for example). Also to interface with flight simulator software like XPlane.

Now they're working on using that interface to drive an autopilot. My question for anyone working on adding autopilot capability to your aircraft: Is it possible that a cellphone or tablet could be used with Avare as the basis for an autopilot?

Many recent phones and tablets have powerful processors along with multiple built-in sensors like accelerometer, compass, and even altimeters. Coupled with internal GPS, might it be possible to use a recent Android device for everything but the servos in an autopilot?