When you need to wake up when it gets dark...

You phone with a light sensor, can up alarm to wake up You, when it gets too dark.

If you need:
- get a nap during a trip, but you don't want to stay overnight,
- you are concerned about safety if the lighting is turned off;

Just start this application and point your phone towards the window. The Alarm wil be up, if the brightness drops below the set threshold.

Additionally, you can see the brightness graph in the app.