It can use camera to monitor everybody and hide/close your game window timely if someone is coming. Of course, it also allows you to press hot key or click mouse to hide/close your game windows
This software is not reviewed yet.
It can be transparent and rotatable. It contains pixels, cm, inch, custom unit. You can also make the ruler not show any unit. It allows you adjust the width and length of ruler. It also includes magnifier. You can use it to magnify anything.