Greenify is a free app for Android that helps you to identify power consuming apps and place them into hibernation when you are not using them. Not only does this stop them from eating at your battery, but it also prevents them from slowing down your device.
Best battery saver app for Android: Greenify
There’s no need to root your Android device in order to use Greenify, but if your device does happen to be rooted then the app gets the ability to do even more.
Android 6.0 Marshmallow users can benefit from even more battery savings by activating a feature called Aggressive Doze Mode with takes the built-in Doze Mode features and, well, amps it up in order to make it even more effective.
I’ve tested this app on a few devices and find that it does what is says on the tin. Battery life is increased with no downside. This is far better than digging through a whole raft of settings in order to get back a few extra minutes of battery life.