Teacher who uses computer can zoom in and increase cursor visibility on screen aside from drawing free lines and displaying keystrokes. Thanks to KDE developers, Plasma desktop has these all enjoyable teaching features built-in since a long time. You do not need to install any application, just enable them on the System Settings. Together these make a complete environment for teaching especially for screencast and live presentation. I make this short article and also a video below to explain how to do that. Finally, if you want this superb teaching ability I suggest you to use Kubuntu the friendly operating system on your computer. Happy teaching!