Paranoid Android is a custom ROM renowned for its huge array of features, one of which you can actually install as a normal Android user without needing a rooted smartphone and flashing a custom ROM. The feature, similar to the Moto X Active Notifications, is an energy-efficient way of giving you a glimpse at your notifications without unlocking your phone: it’s been very appropriately named Notification Peek.
The feature originates from the beta 1 build of Paranoid Android 4.2 . All you need is to have an Android device that is running Android 4.4 KitKat. The feature has been ported by developer Zhe Lu from the build over to an APK and can be downloaded just as easily as installing an app from the Play Store, there are just a few extra steps.
First, go into the settings of your Android device and tap on Security. Here, ensure that you tick the box for Unknown sources.
The APK worked for me on the HTC One (M8), except it did force close more than once. Keep in mind though that this is a work in progress, so hopefully the developer will keep on working on it, because it really is a nice minimalistic, yet super energy-efficient application that many would be able to take advantage of, even if they don’t want to flash Paranoid Android.