1. Swipe down from the top of the home screen to bring up the settings window. You may need to swipe down from the top-right side of the screen.
2. Tap the gear icon at the top, then tap Apps under the Device subheading.
3. Swipe to the left until you’re on the Running tab. Tap Show cached processes at the top to see background apps.
4. Tap individual apps in this list and tap Force Stop to stop currently running processes and apps. (Again, you should generally let the system when to stop apps.)
5. Swipe to the All tab and tap problematic apps to force stop, uninstall, or cease notifications.