My adult son is mentally retarded (Angelman syndrome), but enjoys looking at photos and videos on his iPad. However, he does not understand that he has several fingers that make unwanted things happen when he moves his hand on the screen. Is there any way to limit the screens perception of finger touch to just one, no matter how many fingers actually touches the screen? What he needs to accomplish is just to wipe to the next picture, not twist or zoom in or anything fancy requiring several fingers.