Dozzzer

Official Doze mode is only for Marshmallow, but Dozzzer brings this powerful battery saving feature to all Androids. Yes, even to your Gingerbread granny!

How it works?
Internet is one of the biggest battery drainers. Dozzzer takes care to cut down connectivity whenever you are away from phone.

Highly configurable

Dozzzer is highly configurable. Go for maximum battery saving or save but get all messages on time.
Eager - activates right after turning screen off
Medium - after 5 minutes of idle, messages may be delayed by ~7 minutes
Lazy - after 10 minutes of idle, messages may be delayed by ~2 minutes

Why we ask for VPN?

Android does not allow controlling mobile data directly on Lollipop and later. We rather use a VPN as a firewall. The VPN is strictly local and does NOT cause any security risks!
The good thing? VPN allows to exclude apps (e.g. Skype or Hangouts) from Doze (Lollipop only).

Dozzzer makes sense even on Marshmallow. With eager settings you can get even more out of your battery.