An unexpected reward today

A few years ago I did a simple telegram bot for a small local city community

I was part of it and I did it just for fun

Today a person from another city asked to get access to the bot

I said:
"Sure, just add it and this how …"

And then added:
"But I have 5$/month running cost on it, could you compensate any amount?"

He paid 45$

Wait, what?!

In reality I solved a really simple problem for the community I was a member of
The bot helps community grow and adds a bit of fun into communication people do daily.

So far it's the best fun project I have done.
And now it has even paid me back)

What is the most fun product you have worked on?