The app filters the blue spectrum on your phone or tablet after sunset and protects your eyes with a red filter. The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times.
Do you use your mobile phone after sunset? Do you use your phone within three hours of your bed time? If yes, then your device might be taking your sleep away. Bluelight from your mobile screens sends a signal to brain to wake up, and makes it difficult for us to sleep at night.