Ask HN: One-person SaaS apps that are profitable?

It was pretty cool to see that many one-person SaaS survived test of time and actually turned into bigger companies. Let's bring it back for 2025.

Editions:

2019 - https://news.ycombinator.com/item?id=19701783

2016 - https://news.ycombinator.com/item?id=11924009