Greenify your Android Phone

Greenify is an app for rooted Android phones that will cause any named application to hibernate when it is no longer in the foreground.

An app can remain running in the background on Android devices even after you think you’ve exited it. That’s all well and and good when the app is a timer or alarm but not so good when it’s a misbehaving app sucking down network data or slowing down your device. This is where Greenify comes in and it boasts that it will allow your Android device to multitask like iOS does. A dubious boast if ever I heard one!


It was easy to configure after installing it, I selected the Facebook app and hibernated it. Greenify causes the app to hibernate after turning the screen off for 30 seconds. Once I launched Facebook again the Facebook logo appeared as if the app was shutdown and it took longer to start. It worked! It doesn’t kill the app. If it did then it might be restarted automatically.

I haven’t been able to figure out if Greenify helps extend my phone battery. Yesterday I carried out a small test which I may have botched. I launched Facebook and then left my phone for one hour with and one hour without hibernating the Facebook app from fully charged. After an hour:

  • 93% battery left with the Facebook app hibernated.
  • 95% battery left without hibernation. (Ooops!)

The difference is small and unfortunately it’s not as conclusive as you might think. During the hibernation test I fired up Ingress to paste a passcode in. I did it as quickly as possible but the Ingress app likely remained running in the background for a time. Could it have chewed through 2% of battery?
Also, charging batteries to 100% is notoriously unreliable. Even though it says 100% the battery may not be at at level.

A better test would be an overnight one starting from perhaps 90% of battery. I’ll also keep an eye on things with Better Battery Stats. That app reported that Google Maps caused several “partial wakelocks”. Unfortunately system apps like Google Maps can’t be hibernated.

This app may not save much battery power but it probably will help people with older phones and slower CPUs, but they’ll have to be running ICS. I guess if they’ve rooted their phone it’s likely they can update the ROM too..

Further reading on reddit and AP.