The "$4 app that puts dots on the screen" part is killing me, like the dot is the problem here and not your phone's shutter speed. Cats move fast, man, and phone cameras in normal mode just aren't built to freeze that. Your cousin basically sold you on a flashlight with extra steps. Treats on a string might actually work better since you can control the pace and get your cat to pause right before he jumps. Or just film video and grab a frame from it later, that's what I'd do instead of wasting another 200 shots.

Honestly your old boss was probably right to send that letter, a non-compete is a contract and you signed it, napkin or not. Sounds like the system worked exactly how it should, you broke the deal and he tried to hold you to it. If people could just ignore contracts whenever they felt like it, small businesses would get walked all over.