1. System UI Tuner lets you hide status bar icons and tweak the Quick Settings
There is a neat hidden menu on your new Android Marshmallow phone or tablet that gives you a bit of control over your status bar and its pull-down menus — the System UI Tuner.
Once enabled, you can change the way your status bar and pull-down settings look and feel, giving your Android a more custom feel that would have previously required some rooting and flashing.
Pull down your quick settings — either swipe down on the notifications then swipe again, or use a two-finger swipe. In the top right, you'll see the gear icon. Tapping it is a shortcut to your settings, but tapping and holding it for a few seconds will open a hidden menu in settings.
Long press that gear until you see it spin, then keep holding until you get a pop-up toast message telling you "Congrats! System UI Tuner has been added to Settings."
2. APP permission
You can change the permissions that apps can access in the main Settings app on your device at any time. Keep in mind turning off permissions may cause apps on your device to lose functionality.
3. Doze & Standby
Enter Doze. If the name reminds you of a pleasant nap while nothing pressing is going on, you've figured out what it is. It's a set of changes and rules that will put your phone to sleep when it's idle, which means you're not using as much of that precious juice from your battery. It sounds simple (and it is) but there are a few things to know.
You won't have to do anything to use the new Doze feature. There are no switches or settings you need to toggle, and once you've updated to Marshmallow it just works. That is, when it's supposed to work. And that's the thing. You won't see any benefit from Doze while your phone is in your pocket and you're working or at school. Things need to be idle, and that means really idle.