The word "offline" has gotten loose. A lot of apps use it to mean "works without an internet connection right now" — while still uploading your data the moment you reconnect. Others mean "the app is a local file, but we still phone home every time you launch it." Some mean "we store data in our cloud but cache a copy locally so the app feels fast."
When we say TeenCycle is offline, we mean something quite specific. There is no server we send your data to. There is no analytics endpoint. There is no remote configuration check. The app does not phone home when you launch it. It does not phone home when you don't.
What leaves your phone with TeenCycle: nothing.
A short audit of everything the app could theoretically transmit, and what it actually does:
- Your cycle data. Stored in your phone's local database. Never uploaded.
- Analytics. None. The app does not record which screens you visit, how often you open it, or how long you stay.
- Crash reports. None. If the app crashes, we don't see it. (We test thoroughly before shipping, which is why this rarely happens.)
- Anonymous usage stats. None. There is no "we share aggregate anonymous data" footnote.
- Push notifications. None — and not because we forgot. Push tokens are a quiet form of phone-home.
Why this matters.
Apps that "anonymize" data still send it to a server. Servers can be subpoenaed. Anonymized data is often re-identifiable. "We don't sell your data" is the second-strongest privacy promise an app can make. The strongest one is: we don't have it.
"The only data nobody can ever ask for is the data that was never collected."
— our internal design principles, line 2
This isn't a posture we can change later. It's wired into the architecture. There's no server codebase. There's no database with your name on it. There's nothing for us to lose, leak, or hand over — because there's nothing we have.
For more on why we made this choice, see the offline-first piece. For the trade-offs it imposes on us (no parent dashboard, no web app, no cloud sync), see what we left out.
