This may seem like a silly question. Sorry, first ever android! Is the only way to "close" a program by hitting the back button? Or the "home" button? Because that's all I can figure out to do. And then when I check running programs it has a long list of apps I thought I had closed. For example, the music player. If I back out of the music player it will go off my screen but I'll continue to hear the music. How do I completely close out a program? Thanks!