Greenify help you identify and put applications of misconduct to hibernation when you do not use them, to prevent them from delaying on your device and leech the battery, in a unique way! They can not do anything without you explicitly launching or other applications, while retaining the functionality at run-time, similar to iOS applications!
Greenify needs a service running in the background to automatically work hibernate. It is designed and implemented extremely light, with an average RAM footprint of less than 5M, and close to zero CPU and battery consumption.
For More Info Google Play
varies with device