Amazon's Fire Phone might be a boon for health apps

Amazon released a new device last week, the Fire Phone, that features four sensors, one at each corner of the front of the device. Using these sensors the phone can track the user’s head movements, and adjust the 3D image on the screen according to the angle from which the user is looking at it.

But these sensors are like cameras, too, according to Amazon. They can sense the length, width and depth of an object in front of it.