I built a browser extension for a hackathon that enabled crypto payments direct to site owners. "registration" was just sticking a formatted payment address in a DNS TXT record, and if you were at a supported website, the extension would light up, and facilitated payment.

I still think it's a neat idea but I can't be bothered to build a real version

I had a similar idea for a library used to collect how much you owe who:

https://github.com/thiswillbeyourgithub/FUTOmeter

You'd love Brave browser then.