This background service allows you to light on or off your device by proximity sensor. You just cover and release the sensor by finger, to switch your device's screen on and off.
Please activates the LightLock by "Setting" > "Location & security" > "Select device admin", and remember to inactivates it before uninstall it.
PS. "Unlock" function not supported at Android 2.3.x
Keyword: Sensor lock, Screen lock, Light sensor, Proximity sensor, Smart lock
1. Fix the issue about unable to unlock at Android 2.x devices.