For those quite nights you want to read books on your mobile phone, Google Play Books is making it friendlier for your eyes. The app is introducing a new Night Light feature. It gradually filters out blue light from your screen to replace that with a warm, amber light as the sun sets. If you use f.lux, the same principle applies. It will automatically adjust to the amount of sunlight based on the time of day to give you the right temperature and brightness.
The feature is available to both Android and iOS readers, you just need to update to the latest version of the app. To turn it on, all you need to do is open a book and select Night Light option from a pop-up that will show up.
Source: Android Official Blog | Download: Google Play Store (Free) + Apple App Store (Free)