Quoted from jalpert:
You know what we REALLY need? A pinball leveling app that works with the iPhone on it's back. Then, every 5 seconds (or set interval) it says the degree pitch. That way, you don't have to get up and down 5 times to know if your machine is level.
I was thinking the same thing. Doesn't have to be voice. Could just be a tone or beeping or something.