The Color Flashlight is a free flashlight app that has quite a few features and is also one of the lowest-permissions-needed apps that you will be able to find. The Color Flashlight app utilizes the camera flash on the back of your phone as the flashlight and cal also turn your devices screen into a flashlight, using a variety of colors, shapes, patterns and sizes.
While it does contain advertising, it is easy to maneuver around and does not contain permissions that will transmit personal data.