Show HN: I built a privacy-first period tracker but it seems nobody cares

My wife once showed me a notification she got from her period tracking app. At first, it seemed like a simple reminder. But then came the ads. Not long after, she started getting eerily specific suggestions on other platforms. Things she hadn’t searched for. Things that felt too close. Somewhere, her cycle had been turned into a data point.

That bothered me more than I can explain.

These apps promise helpful insights. But in return, they take so much. Your private health data, your habits, your patterns. And they sell or share it with third parties. Some even charge ridiculous monthly fees, only to flood the app with ads and tracking scripts.

That moment was the beginning of something for me.

I built Faye because I couldn’t stop thinking about how wrong this all felt.

Faye is a free menstrual cycle tracker built from the ground up with one thing in mind: you stay in control.

Your data stays on your device.

No accounts, no cloud sync, no background trackers.

No ads, ever.

You can export or delete your data whenever you want. No begging, no hoops.

There’s a password lock option.

There’s a discreet mode that makes the app look like a work productivity tool, just in case.

It’s completely free, with no hidden costs.

It’s not just an app. It’s a quiet protest against how the system works.

But here’s the part I didn’t expect.

I shared it with a few people. Some friends. Some folks in tech. Some in health circles. Almost nobody responded. Not about the privacy. Not about the features. Not even about the idea. Some tried it, sure. But it was quiet. Too quiet.

And I started to wonder…

Did I build something only we needed? Is this just a personal itch I scratched, or are there people out there who also want this…really want this? People who care deeply about their data staying theirs - people tired of apps that exploit vulnerability for profit.

I sat with that silence longer than I expected.

It made me question everything. How we talk about privacy, who we build for, and whether anyone notices when something doesn’t try to sell them something.

Because when you strip away the dark patterns and the dopamine loops, there’s no reward system left. No notifications engineered to pull you back in. Just a quiet little app, trying to do the right thing.

And maybe that’s the problem. Or maybe that’s the point.

I still don’t know.

I don’t know if I built something only we needed. I don’t know if people really want privacy. I don’t know if “doing the right thing” is enough to make something last.

What I do know is that I couldn’t unsee what I saw. I couldn’t forget that feeling, that jolt, when I realized how casually something so personal was being harvested and sold.

So I built the thing I couldn’t find. I put it out there.

And I’m sharing this, not as a launch or a pitch. Just as a note from someone who built something they believe in, and is now standing in the quiet, hoping it might matter to someone else too.

If that’s you, I’d really love to know. Even just a quick reply telling me you get it would mean a lot.

And if you think someone else in your life might care; a friend, a sister, a partner… maybe share Faye with them.

It’s not a 100-million-dollar idea. But it’s honest. And built with care.

https://faye.health/period-tracker