If your battery isn’t giving juice to Android through the day, Greenify is an app which automatically hibernates the background apps to save your Android battery juice. It is not a task killer or it doesn’t freeze apps like Titanium Backup, it just hibernates the apps. It helps you identify the bad behaving apps and stops them from lagging your device.
Some apps that need to stay running in the background like messaging, emailing or alarm apps, but for other apps, this is a great option. Greenify is a free app available in Google Play Store and needs root access for functionality.