Greenify by Oasis Feng
If you are using a rooted Android phone, you can improve performance and extend battery life using an app called Greenify that hybernates (rather than killing or freezing) whichever apps and processes you are not using at the moment.
Recommended by Lifehacker: http://lifehacker.com/greenify-auto-hibernates-apps-youre-not-using-to-save-513922193
Here’s the link: https://play.google.com/store/apps/details?id=com.oasisfeng.greenify