With the upcoming release of iOS7, every app icon and app UI has been changed in some way to reflect Jony Ive’s new flat design of the mobile operating system, working with gradients and flat images, rather than realistic renders.
FaceTime is one of the first patents found, instead of the grey design with the camera lens, bringing in multiple layers of focus, the icon has been redesigned with a green gradient and a white FaceTime logo. It draws a lot of similarity from the iPod touch iOS 4 icon.
Apple will be releasing iOS7 to everyone this fall, even though Apple developers have got an early sneak peak at the beta. Compliments and criticism have been all around the update, as they are with everything Apple does.
Source: Patently Apple