There's really not much to the Windows Phone 8 app Accelerometer Toy but still, it does a nice job of things. It's a utility app of sorts that simply demonstrates your Windows Phone accelerometer in action.
Accelerometer Toy does so in two ways. First you have the Readings Page that displays the X, Y, and Z axes and the associated readings that illustrates the Windows Phone's current orientation. The axis readings spin about like a Tasmanian Devil but there is a stop button in the lower right corner should you need to stop things should you need to get an easy to read value.