Oddly enough my least valuable project was my most successful (so far, I hope!). It was a tinker project while I was learning Laravel, no target market at all.

It was very specific - a database/API of YouTube videos and metadata for a YouTube group, the Yogscast.

It ended up being used as the backend data for a viewer-controlled cinema that let users vote on and pick videos to watch during livestream downtime to keep the audience engaged during a charity drive.

Can't take much credit, of course the actual video playing code was the meat and potatoes of the operation during downtime and the actual stream content during the daytime, but it was vaguely involved in raising millions for charity haha

Regrets none, only reason it's not still about is that it turns out YouTube don't like you making a database of YT videos that you allow others to access, they killed my API key eventually