It's easy to take always-on displays for granted. Long gone are the days of flashing notification lights, customized down to individual apps. Instead, the AMOLED displays that are nearly universal across the best Android phones fill that role for us, showcasing incoming messages, weather alerts, calendar reminders, and — of course — the current time. It's a much more advanced system of keeping you notified while simultaneously keeping you from having to touch the display at all.
