The screens of the iPhone, iPod touch, and iPad — with their crisp, bright, touch-sensitive display — represent masterpieces of engineering. The multitouch screen common to all iOS devices provides one of the key factors in the platform’s tremendous usability. Because the screen can detect multiple touches at the same time and track them independently, applications are able to detect a wide range of gestures, giving the user power that goes beyond the interface.
Suppose you are in the ...