Lichtwecker is a simple alarm clock which wakes with the backlight of a smartphone. Via a sequence of adjustable duration, during which the backlight lights up slowly, the awakening can be made more pleasant.
Attention: Consider the EULA ( http://cygery.com/wordpress/apps/legal/eula/lichtwecker/ ). Never rely on getting waked by this application. Always use another alarm clock you can rely on.
Everybody reacts different on ambient lighting. Therefore you should test different settings to find out which suits you best. Generally it's recommended to use this alarm clock in a completely darkened room to avoid disturbing influence of other light sources. The smartphone's position and orientation also have an impact on the functionality. A too close position with the display lighting directly on the eyes might be adverse because you awake on the lowest brightness level. On the other hand, a too great distance might render the application useless (because of the inherent low luminosity of the backlight).
RECEIVE_BOOT_COMPLETED: For reactivation of the alarm after a reboot or to show a notification if the alarm was missed.