When I finish using firefox on my android phone, I tell android to close it. It disappears from the screen and the recently used apps list, so then I ask cleanmaster to scan for running apps, and firefox is still active. Supposedly, cleanmaster hibernates the app. Just to be sure, I go through the battery check to see what is still running, and firefox is still running. I tell the battery checker to hibernate it. At this point, I'm not really sure that it is hibernating or not running. What can I do to quit firefox completely when I'm not using it?