Is there a freeware program that will allow me to simply hold down a key to restrict my mouse movemement to either the X or Y plane?

Like, hold down Shift, for example, and I could only move my mouse up and down exactly, or left and right exactly. If so, where can I download it? I used to have this functionality on my old laptop with the touchpad controls, but I don’t now, and I want it back. It was so useful.