Apple has opted to have the controls available to developers via AVCaptureDevice APIs.
No need for Apple users to keep their camera settings automated because with iOS 8, you are going to get manual settings for your camera. Previously, only some basic settings such as flash and HDR mode allowed for manual adjustments. Thanks to the upcoming iOS 8, we are going to get all manual camera controls opened up including ISO, shutter speed, focus mode, white balance, as well as exposure bias.
However, it must be kept in mind that these advanced settings are not going to be available in the iOS 8 native camera app. Instead, these controls will be available to developers via AVCaptureDevice APIs. This means that we can be expecting some third party photography apps to arrive at the latest iOS similar to the Nokia Camera. As far as the native iOS 8 camera app is concerned, it will only gain exposure bias controls.