100 Users for a Tiny Tool I Almost Didn't Build

Just crossed 100 users with a small tool I built to solve a problem that kept annoying me.

I kept running into websites that were trying to manage AI crawler access, but the setup was messy. Some site owners would block one crawler and accidentally block others they actually wanted to allow. There wasn't a simple way to create a clear policy file without manually editing rules.

So I spent a weekend building a generator that creates a clean configuration file for AI crawlers.

A few things surprised me:

The problem was more common than I expected.
Most users wanted simplicity, not dozens of advanced settings.
The first 100 users came mostly from conversations and community posts rather than paid promotion.

The biggest takeaway for me is that small frustrations are often better startup ideas than grand visions. If something repeatedly wastes your time, there's a decent chance it annoys other people too.

Curious how others validate these kinds of niche tools. What was the smallest problem you've solved that unexpectedly attracted users?