While in an application (full screen or windowed) you can tap the top button on the front-left that has the two squares on it. This will bring up the app switcher menu as if you pressed the icon in the bottom right corner of the screen. If you hold it, it will minimize all windows and "Return To Home".

As for a way to duplicate the action when you hit the Fullscreen button on the top of the device, I usually don't have much difficulty. Admittedly, it is sometimes harder with the screen open.
Some (if not all) of the applications should have an option within the Menu to switch the view between Full and Windowed. In Tear, for example, tap on the menu bar (or menu button on the keyboard), go to View, then Full Screen. Not exactly a quicker way then the HW button, but may work in some cases when the screen is raised.