Reaction

Reaction keeps a computer looking active while you are away from the desk. The cursor travels along smooth curves with micro-pauses, navigation keys are pressed at an uneven rhythm, pages scroll and windows are switched in turn, so the screen keeps changing the way it does when a person is working. Where a classic mouse jiggler repeats one movement on a timer, Reaction varies timing, speed and pauses, and runs key scenarios written by hand for each application family it recognises - 24 profiles covering 60+ application names. It acts only while the machine is genuinely idle and stops instantly when you touch the mouse or keyboard. A hidden mode runs it with no window and no tray icon; global hotkeys pause and restore it. Reaction records nothing: no keystrokes, no screenshots, no file access. Windows 10/11 and Linux, one paid plan with a 14-day free trial.