iOS 7/8 style blurred view controller that appears on top of your view controller.
Live Blur - By default, live blurring is enabled under iOS 7. The live blurring is performed by using a UIToolbar as a background view, that means when you change its tint color, it becomes desaturated. That's the way it works on iOS 7. iPhone 4 doesn't support live blur and falls back to a transparent view. This also applies to when a user device has high contrast accessibility setting set to on.