Must have if you're Rooted

App hybernates applications when not in use.  Basically, it stops the apps from running in the background, draining your battery, and eating up data. So when it comes to "boosters and battery savers", Greenify does it better than any of them.

You can easily choose which applications you want to hybernate and create a one tap widget for your home screen, that will hybernate all of your preselected applications all at once.