Most certainly, too many to count. A few are on github, e.g. https://github.com/lgommans/mountall.sh, various others are on https://lucgommans.nl/p/
If you're just having a look around, I might recommend to start with
- the hangman solver as a funny random example https://lucgommans.nl/p/hangman-solver/ (for a game to try it on: apt install bsdgames && hangman)
I use 'cau' a lot myself for 'inline' footnotes in chats, e.g. https://lgms.nl/p/cau/?Look+at+how+much+data+I+can+fit+in+th.... but I could see how most people would not use my server for that. Feel free to steal the code! https://lgms.nl/p/cau/?source
I'd be curious to know how many people haven't made the equivalent of https://lgms.nl/p/ip/, at least if you're from before when icanhazip became popular