The v2.8 update to Greenify has been in testing for a few months, but the final version is rolling out at long last. This app began life as a root utility to forcibly hibernate apps, but it has slowly gained more non-root features. In v2.8, it can supposedly accelerate Marshmallow's Doze mode so it kicks on in just a few minutes. That's just the start; there's plenty more, especially if you're rooted.
Here's the changelog for the latest update.
- 2 new experimental features for Android 6.0: Aggressive Doze (no root required) & Shallow Hibernation (root), pushing the power-saving beyond Marshmallow.
- Seamless auto-hibernation experience in non-root mode. (no flicking on screen any more)
- Nav-bar gesture for Android 6.0 (in settings).
- New option to toggle "screen off" implementation. (root)
- Improved the "working" state detection logic.
- The Tasker plug-in should now work with more compatible tools.
- New wake-lock-free hibernation engine.
The aggressive Doze mode can be activated in the experimental menu. I've activated it on a Nexus 5X, and it does appear to be dropping into Doze after about five minutes of sleep (you can have it notify you with Dose times). I can't yet say if it will cause any other issues. The application hibernation process has been streamlined for non-rooted users too—no more flick gestures on the screen to trigger Greenify.
The new version is still rolling out in waves on the Play Store, but we've got the updated version on APK Mirror if you want to go that route.