We want the user interface to be as immersive as possible so we just managed to reclaim all the 768 x 1024 screen real estate of our Tabtronics mini Android tablet (shipping with Android 4.2.2). In the picture below a simple Processing app draws the screen diagonals.
Since Processing can only use Android API Level 10 (which excludes the more recent immersive mode) and these types of tablets force the system bar for critical navigation tasks (as often they don't have HW navigation buttons), this required gaining admin access and then using a tool to run the app in Kiosk mode.
