License Key Implementation for own Application

Hello, I’m new here in the forum. I’m working on a small tool that I would like to protect that it is more widespread without my knowledge. That means I would like a kind of license key input realized. Is there a simple solution without much effort and without tool from a third party? That also does not have to be particularly tamperproof. It should just not be circumvented by any little child.

Thank you for your answers,

Mac or Windows? Have you heard about AquaticPrime?

I would need it for Windows and Mac. But if I have to choose than Windows on first place. Thank you for the tip with AquaticPrime I’ll give it a closer look. But so far as I have seen it is for Mac only, am I right?

For something that is very simple, check out RegCode.

Thank you very much Paul. Exactly that I was looking for. It amazes me that I have not found here in the Forum. Thanks for the quick replies!