BetterMouse makes whatever window you want move instead of your mouse, reducing eye strain from moving back and forth, so you only need to look at the center of your screen.
TO run the program, download the latest release and run it via
java -jar BetterMouse-1.0.0.jar "Title"
With "Title" being some text in the window title you want to control. To exit out of the program, press the Escape key.
There's also a reddit post on r/badUIbattles showing it off.