"Non-typical" projects on IH?

I think we all know what is a "typical" IH project. Some kind of marketing tool, some kind of "no-code" sass, yet another productivity tool, "minimalistic" CRM, sales-for-developers newsletters etc.

On the other hand I am building something very atypical - website for people learning university level mathematics.

I believe that making indie project is a great platform for very creative / non standard ideas, because we don't risk much (apart from loosing time) and we don't need a lot of income to become sustainable (compared to a typical company).

So what are some projects on Indie Hackers (either yours or somebody else's) that you believe are nice examples of being "non-typical" on IH?

It would be cool to find each-other, support and look for creative solutions together. :)