A free program for Android, by JK.Fantasy.

The Screen Light and Breath Light app is an application that allows you to set up a screen that will enable you to easily fall asleep. If you have a problem with insomnia, this app can help you by letting you follow the light and shade. It will then help you to lessen tension so you can eventually fall asleep.

The app has a simple user interface, and you can easily set up your preferences. There are two modes that you can use. First is the Light Mode where you can select whether the brightness of the screen is fixed or choose Breath for breath light. Second is the Color Mode where you can select a color, or set it to Dynamic if you want the color of the screen to change gradually.