Greenify is a utility app for Android devices that helps maximize battery life and improve device performance. It was featured as Lifehacker's Top 1 Utility in 2013 and Android Authority's Top 3 Best Root Apps. The app offers features like "Aggressive Doze" and "Doze on the Go" to optimize battery saving on Android 6+ devices, even without root access. By identifying and putting misbehaving apps into hibernation when they are not actively being used, Greenify prevents them from slowing down the device or draining the battery. The app ensures that hibernated apps can only run when explicitly launched by the user or other apps, preserving their full functionality when in the foreground.

Greenify does not collect personal data, despite its use of the accessibility service. It only utilizes this service to automate the hibernation process. It is important to note that when an app is greenified, its background functionality, such as services, periodic tasks, event receivers, alarms, widget updates, and push messages, will be disabled during hibernation, except when the app is actively being used. Therefore, it is recommended not to greenify alarm clock apps or instant messaging apps unless they are not relied upon. Users are advised to verify the impact of greenified apps on which they heavily rely.

The app requires certain permissions to function properly. It uses the device administrator privilege to turn off the screen immediately after automated hibernation on non-root devices. The "draw over other app" permission is used to dim the screen during automatic hibernation when the screen is expected to be off. The "disable screen lock" and "bind accessibility service" permissions are necessary for automatic hibernation to work on non-root devices. Additionally, the app requires the "get accounts" and "write sync settings" permissions to control the account sync of apps if their sync tasks are too frequent. Greenify also utilizes accessibility services to automate the hibernation procedure.

Greenify offers a donation package for users who wish to support the app and gain access to extra experimental features. These features include the ability to greenify system apps, in-depth details about how apps behave on the device, and more. The app's translations are created by community volunteers and are open for contribution. Users can report bugs in the XDA forum or the G+ community.