I wanted to call it pervitin but then I learned about the ugly historical connotation.
I feel like I'm missing something because I don't understand how this wouldn't be just an OS system setting. Certainly not an app that you would pay for (or use an example of some great feature). That's just a option in KDE's system settings. And when I used to use Gnome 3, and Unity before that, and Gnome 2... just a setting.