I have a LG Optimus 3D Max P725. I can’t close the apps that are running on my phone. I just press the "back" key. I know that if I hold down the home button, I get the last 6 applications that were opened, but does this mean that these 6 apps are currently open? Is it like pressing CTRL ALT DEL on a Windows PC? Or does it just show the last 6 apps that were opened? Please help me.