When the iPad is lying on the table the accelerometer is not moving, that is right. Well, the accelerometer is not measuring movement or speed or anything like that, in fact it's measuring forces. For example even if your iPad is glued to the floor it will show you that earth's gravitational force is acting on the y-axis (i think). That is btw how the accelerometer is helping to calculate the orientation of the iPad (I think many people believe that it is measuring that you turn the iPad around, when in fact it is just measuring that the gravitation is acting on a different axis).I don't see how that would work either? if the ipad is on a table it won't be moving?
It should work very well.