Privacy Policy

Last updated: 5 June 2026 · Effective: 5 June 2026

1. Overview

CycleSync ("we," "us," or "our") is a mobile application developed and published by Tunnxo. This privacy policy explains what information CycleSync handles, how it handles it, and the choices you have. The short version is above; the long version is below.

CycleSync was designed around a single principle: your reproductive and cycle data is uniquely sensitive, and it should stay under your control. Every architectural choice in the app reflects that.

2. Data we collect

CycleSync collects the minimum information needed to function. Specifically:

Cycle data you log — period start dates, cycle length, optional symptoms, focus/rest preferences per phase. Stored locally on your device.
App preferences — theme, notification settings, paywall-dismissed state, and other in-app settings. Stored locally on your device.
Subscription metadata — your Pro entitlement status and the originating store (Apple App Store or Google Play). Provided by RevenueCat and stored locally.

We do not collect names, email addresses, phone numbers, dates of birth, or any contact information. CycleSync does not require an account.

3. Data we do not collect

To be explicit, CycleSync does not:

Collect your name, email, phone number, or any contact info.
Require an account, password, or login.
Sync your cycle data to a server.
Track your location.
Use third-party analytics that follow you across apps.
Sell, rent, or share your data with advertisers, data brokers, or social networks.

4. How your data is used

Data stored on your device is processed locally and is used only to power the features you see in the app — phase prediction, conflict detection, reschedule suggestions, insights, and notifications. It never leaves your device.

Subscription metadata is exchanged with RevenueCat (see below) so the app can know whether you have an active Pro subscription. We do not collect or store your billing information — that lives only with Apple and Google.

5. Health data (Apple Health & Google Health Connect)

If you choose to connect a health platform, CycleSync can read menstrual-cycle data to improve phase predictions. CycleSync is read-only — it never writes to Apple Health or Google Health Connect, and the only data type it requests is menstrual cycle / bleeding records.

Permissions

Apple Health (iOS): we request the menstrualFlow read permission. You grant or deny this in the system Health dialog.
Google Health Connect (Android): we request read access to MenstruationRecord and IntermenstrualBleedingRecord. You grant or deny per data type in the Health Connect dialog.

Storage

Health data read from these platforms is merged into your local cycle log and stored on your device. It is not uploaded, shared, or transmitted anywhere.

Revoking

You can revoke CycleSync's access at any time:

iOS: Settings → Health → Data Access & Privacy → Apps → CycleSync
Android: Health Connect → Apps → CycleSync → Permissions

6. Calendar data

When you connect a calendar, CycleSync requests permission to read events. We use this to overlay your schedule with cycle phases and detect conflicts. Calendar data is read at request time and held in memory only — events are not stored on our servers (we have none) and are not retained longer than needed for the current view.

Pro features that reschedule events require an explicit, individual confirmation per event. We never batch-move events, and we never delete events from your calendar. You can disconnect a calendar at any time in app settings, which stops future reads.

7. Subscriptions & payments

CycleSync Pro is sold as a subscription through Apple App Store and Google Play. We use RevenueCat to manage the entitlement, which is the industry standard for cross-platform subscription handling.

What RevenueCat receives

An anonymous, install-scoped identifier (no name, email, or device fingerprint).
The store-issued purchase receipt, used solely to verify your subscription status with Apple or Google.

What RevenueCat does not receive

Your name, email, or contact information.
Your cycle data, calendar data, or app preferences.

RevenueCat's privacy practices are described in their privacy policy.

Refund policy

Refunds are handled by Apple and Google, not by us. Use the standard store channels to request a refund; we cannot issue refunds from inside the app.

8. Notifications

CycleSync schedules local notifications through your device's notification system. These are generated and delivered entirely on-device. We do not use a remote push notification service, so no notification metadata is sent to us or to any third party.

9. Third-party services

The only third parties involved in CycleSync are:

Apple App Store / Google Play — for distribution and subscription billing. Their privacy practices apply to your store account and payment data.
RevenueCat — for subscription entitlement verification. See above.
Apple Health / Google Health Connect — for optional cycle-data integration, only if you connect them.

CycleSync does not embed third-party analytics, advertising SDKs, crash reporters that ship user data, or social media widgets.

10. Your rights & controls

You can exercise the following rights at any time, without contacting us:

Access — your data is on your device. Open CycleSync to see it.
Export — Profile → Export Data exports your full cycle log as JSON or CSV.
Delete — uninstalling the app removes all locally stored data. There is nothing to delete on a server because we have none.
Disconnect — disconnect calendar or health integrations in app settings, or revoke at the platform level (Apple Health, Google Health Connect, iOS / Android system settings).
Opt out of notifications — in-app notification settings, or at the OS level.

If you have a Pro subscription and wish to delete it, cancel via the store first (App Store or Play Store), then uninstall.

11. Children's privacy

CycleSync is intended for adults. The App Store age rating is 17+ (iOS) due to medical/health content; the Play Store rating is "Everyone" with medical content disclosure. We do not knowingly collect information from children under 13. If you believe a child has provided information, contact us and we will work with you to remove it.

12. International transfers

Because CycleSync does not transfer your cycle or calendar data off your device, no international transfer of that data occurs. Subscription receipt data may transit RevenueCat's infrastructure (US-based), but no personal or health data is included in those transfers.

For users in the European Economic Area, United Kingdom, California, or other jurisdictions with specific privacy laws, CycleSync's local-first design is intended to minimize the obligations and risks on both sides: we hold no personal data, so there is little to disclose, amend, or delete.

13. Changes to this policy

We may update this privacy policy as CycleSync evolves. When we do, we will revise the "Last updated" date at the top of this page. For material changes, we will also surface a notice in the app on the next launch. Continued use of CycleSync after a material change indicates acceptance of the updated policy.

14. Contact us

If you have questions, concerns, or requests about this privacy policy or your data, contact us at:

Email: privacy@cyclesync.app
Support: cyclesync.app/support

We respond to privacy requests within 30 days.