InvisiBright is an invisible brightness adjustment utility for your Android phones. You can adjust the screen brightness from inside any application by either swiping across the screen or tilting your device. You can save your device battery by keeping brightness in check for screen brightness.

Features;

• Status bar shortcuts
• Tilt and Touch Modes
• Highly customizable preferences
• No background services.

Here is a video of app in action;

Download InvisiBright