After installing CameraTweak 3, the functions are enabled by default in the camera settings. Just open your camera application, you will see some new UI / button elements that allow you to do some interesting things. If you touch the camera button to the left of the shutter button you will see a menu, which will be different depending on whether you are on "Photo" or "Video". In the tweak there are many features, some of which are already available within the Camera diiOS 8 app itself. Here is the detailed description of what you will see by pressing the camera button while you are on photos / videos.