Apple is Testing Motion detection features in iPhone
Apple is testing motion control features which will let people to control their iPhone with the movement of their heads. This feature works with the help of front facing iPhone or iPad camera that detect head movements.
When the head is moved to left or right it assigns different types of tasks such as displaying notifications, returning back to home screen etc.
Thus, navigating phone interface through head movements seems to be useful for people with limited mobility that make touch or voice interfaces difficult to use.