Not sure if "successful", but https://newbusinessmonitor.co.uk/ makes me some pocket money — not nothing; half-way to "Ramen Profitable" — and was also accepted into the Advisory Track of this year's YCombinator Startup School which I'm quite proud of. I did a Show HN in May last year, and I can't believe how ugly and crappy the service was back then in comparison with how it is now.
This reminds me that I should document the history of projects I work on.
This reminds me that I should document the history of projects I work on.