Android: We all know that screen brightness has a huge effect on your phone's battery life, but Android's built in auto-brightness setting isn't always accurate, and doesn't offer anything in the way of customisation. Velis Auto Brightness on the other hand oozes customisability, and gives you in-depth control over your screen's brightness.
The app's main screen consists of a curved graph and two handles. Dragging the handles changes how bright your screen should be at different levels of ambient light. If you want to save on battery life for example, you could make sure that your screen never jumps to 100 er cent brightness, even in direct sunlight.
Digging deeper, you can create custom profiles for different situations. So for a typical day where you could plug in your phone at your desk, you might allow the screen to be brighter than when you're out on a camping trip. There are literally dozens of other minor settings to dig through if you really want to get technical, but for nothing more than the customisable profiles, this app is a no-brainer for all Android owners.