Twilight is an Android app that automatically adjusts your device's brightness (technically, its colour temperature) over the course of the day, reducing the harsh whites and blues as the day progresses. We've talked about how to avoid eyestrain at the computer, but when you're not staring at a computer screen, you're probably looking at your phone or tablet, and Twilight can help.
Once installed, the app slowly adds a soft red filter over your display as the hours drag on. In the morning, your phone or tablet's screen will be bright white, but the app filters out the blues over time to try and reduce your exposure to the kind of bright, harsh light that keeps you awake at night and prevents you from falling into a deep sleep. The intensity of the red filter adjusts automatically, and is based on the sunset and sunrise times where you live. We tried the app out, and it works as advertised, although it takes a little getting used to at first.
Twilight is a bit like F.lux (another app we love) for Android. It was developed by the same guy behind Sleep As Android, one of your favourite sleep tracking tools. If you want to give it a shot, it's free and available now at Google Play.