OK well the manual is very basic, and doesn't cover everything. The back button doesn't necessarily close the app. it depends on the app being used, but the app may still be running in the background. I would say the home key is more like the end-call key on a Symbian phone. this takes you to the home screen, but leaves all apps running in the background.The phone does not come pre-installed with a file manager, but that's the beauty of Android. You are free to use Market and download a file manager of your choice, A good one is Astro, its free and it has a process manager, that can be used to close unnecessary running aps, and those that don't close when you back all the way out of them.Don't forget the menu key, the one one the left, in different apps, it gives a menu with additional functions eg. delete.