A free program for Android, by Ardentic.

Night Mode – Blue Light Filter is a useful application that allows you to filter out the blue light that comes from the screen of your phone or tablet before it gets to your eyes. This will help you to read more comfortably and help you to have a good night’s sleep.

If you are one of those people who have a hard time falling asleep or who have a habit of waking up at the slightest noise or a slight light, then this app is just what you need.

The reason why this app is so effective is because it lets you filter out the blue light that comes from the screen of your phone or tablet.