SuperFreezZ is an open source alternative to Greenify that kills apps running in the background
Task managers are widely viewed as unnecessary on Android smartphones. Most of us may agree with that view, but the reality is there are still a lot of misbehaving Android apps out there, most task “killers” don’t actually do anything useful besides clearing the recent apps view (which doesn’t really “kill” apps anyway), and a lot of users have yet to upgrade to newer Android versions that have implemented more restrictions on background apps. That’s why, to this very day, apps like Greenify and Brevent remain incredibly popular. Many users swear by both Greenify and Brevent, but since they’re closed source, some users are wary of them. If you’re looking for an open source alternative, check out SuperFreezZ by XDA Junior Member hcur.
The app works just like Greenify does in its non-root mode. It uses an Accessibility Service to automate going to Settings and force closing apps. You can optionally allow the app to access the UsageStats API so it can detect and kills only infrequently used apps. Call it “freezing,” “hibernation,” or whatever you want, SuperFreezZ kills the apps of your choosing that are running in the background. In the app’s settings, you can enable freezing of apps when the screen turns off, which requires disabling the “power button instantly locks” option, and you can change the time in days an app must be inactive for it to be killed.
Just because an app has been force closed by SuperFreezZ doesn’t mean it can’t start back up again, especially on Android Nougat. There’s a way to prevent an app from waking up in the background on older Android versions, but it requires the use of a hidden ADB command. Alternatively, you can fully disable any app, even system app bloatware, to prevent it from ever running. If that’s too complicated, then you can use apps like Shelter or Island to isolate apps using Android’s native Work Profile feature.
There are many different ways for power users to take control of the apps running on their device. An app like SuperFreezZ is just one of many options. Even if it’s not the most powerful or robust, it’s free and open-source, and that may be enough of a reason for some of you to install it. You can download the app from F-Droid or compile the app from its source code on GitLab. If you have any questions, you can post them on the XDA forum thread.