Privacy Policy
Last updated: 28 August 2026
CycleSync ("the app") is a personal menstrual-cycle tracker that projects your cycle phases into your own Google Calendar. This policy explains exactly what the app accesses, what it stores, and what it never does.
Who runs this app
CycleSync is operated by an individual developer, not a company. There is no backend server, no database, and no user accounts. Questions: ajf.zlamal@gmail.com.
What the app accesses
Your Google account identity
When you click "Sign in with Google", Google shares your name, email address, and profile picture with the app so it can show which account is signed in. This information stays in your browser for the duration of your session and is never transmitted to the developer or any third party, and never stored anywhere.
Your Google Calendar
The app requests the Google Calendar scope
(https://www.googleapis.com/auth/calendar). It uses this access only to:
- create a single dedicated secondary calendar named 🌸 Cycle Tracker in your account (if it does not already exist);
- add all-day "phase" events (Menstrual, Follicular, Ovulatory, Luteal) to that calendar for roughly one year ahead;
- find and delete the app's own future events on that calendar when you recalculate your cycle or reset the app.
The app identifies its own events by a tag it writes into each event's description. It does not read, modify, move, or delete any other calendar or any event it did not create.
What the app stores
-
Your cycle start date is saved in your browser's local storage
(
localStorage) on the device you use. It is used only on your device to calculate the current phase. It is never sent to the developer or anyone else. - A short-lived Google access token is held in memory during your session so the app can talk to the Calendar API. It is discarded when you close the tab or sign out.
The app keeps no history on any server because there is no server. Your phase events live only in your own Google Calendar, under your control.
Third-party services
- Google — sign-in and the Calendar API. Your use of these is governed by the Google Privacy Policy.
- Static web host (e.g. Cloudflare Pages or Netlify) — serves the app's HTML/JS files. The host may record standard web-server request logs (such as IP address and browser type). The app sends no data of its own to the host.
- cdn.tailwindcss.com and Google Fonts — load styling and font assets. These providers may see your IP address as part of a normal asset request. No app data is shared with them.
What the app never does
- No analytics, tracking pixels, or advertising.
- No selling, renting, or sharing of your data.
- No profiling, and no use of your data to train any model.
- No access to your email, contacts, files, or any Google data beyond the Calendar scope above.
Retention and deletion
- In the app, open Settings → "Clear Calendar & Reset Data" to delete the app's future events from your 🌸 Cycle Tracker calendar and clear the locally stored start date.
- Revoke the app's access to your Google account at any time at myaccount.google.com/permissions.
- Clearing your browser's site data for this app removes the locally stored start date immediately.
Children
CycleSync is not directed to children under 16 and does not knowingly collect data from them.
Changes to this policy
If this policy changes, the "Last updated" date above will change. Material changes will be noted on this page.