What it is
Period Or Not is a period tracking app with one rule: your data stays on your device. No accounts, no cloud sync, no analytics, no data selling. Zero-knowledge encryption. Just a simple tracker that does its job and keeps your business private.
Why I built it
Period tracking apps became a privacy concern after Roe v. Wade. Most popular trackers sync everything to the cloud. I wanted to build something where the data literally cannot leave your phone.
How it works
Log your period, get cycle predictions. The app learns your patterns over time and gives you insights on your home screen. You can export data for backup and optionally sync with your calendar, but everything stays local.
The pivot
The app originally had partner calendar sharing. In version 3.0, I stripped it out entirely. The more I thought about it, the more I realized sharing features created attack surface for privacy. So I deleted them on purpose and went fully local with zero-knowledge encryption instead. Less features, stronger promise.
Design approach
Minimal UI, fast logging. Open the app, tap, done. The home screen shows cycle insights at a glance without making you dig through dashboards. Dark and light themes both ship, and the app follows your system setting.
Built with
React Native, everything on-device. No Figma file exists for this one. I designed it straight in code, screen by screen, adjusting in the simulator instead of in a canvas. That’s the part I’m most proud of.
Legal
Privacy Policy — what the app stores, and why none of it reaches me.
Terms of Service — licence, purchases, medical disclaimer, liability.