Privacy Policy

Effective date: 2026-06-18

Short version: Chronosync Plus is designed as a local-first iPhone app. We do not require a Chronosync account, do not sell personal information, do not use the advertising identifier (IDFA), and run no analytics or behavioral tracking SDKs. The only third-party SDK is Google AdMob, used solely for an optional rewarded video you can watch to unlock the free trial.

1. Scope

This Privacy Policy explains how Chronosync Plus handles information when you use the app, website, support pages, and related services (collectively, the "Service"). Chronosync Plus is an educational wellness app related to circadian rhythm, light exposure, estimated vitamin D production, UV context, solar alarms, sleep timing, and night routines. It is not a medical device.

2. Information stored locally on your device

The app stores most user data locally on your iPhone using the app's local storage. This may include:

Approximate or precise location coordinates you enter or allow the app to use.
Place name, timezone, sunrise, solar noon, sunset, and other calculated solar data.
Chronotype, Fitzpatrick skin type, clothing coverage, age range, and other onboarding choices.
Sun-session logs, estimated vitamin D IU, estimated UV exposure, and estimated burn-time values.
Sleep and wake times you choose to log.
Ambient-light readings or estimates used for morning-light tracking.
Alarm settings, notification preferences, blue-blocking glasses preferences, and reminder state.
Circadian score history, trend snapshots, and app settings.

We do not operate a Chronosync user-account server that receives or stores this local profile. Anyone with access to your unlocked device may be able to view local app data, so use your device passcode, Face ID, or Touch ID to protect the phone itself.

3. Information sent to third-party services

Some features require public data lookups. Depending on your settings and use, the app may send latitude and longitude, timezone information, or a place query to the following providers:

Provider	Information sent	Purpose	When
`api.open-meteo.com`	Latitude and longitude	Current UV, UV forecast, cloud cover, and weather context.	When the app needs weather or UV data for the selected location.
`nominatim.openstreetmap.org`	Coordinates or search text	Reverse geocoding and place-name lookup.	When you search for, set, or display a location name.
`timeapi.io`	Latitude and longitude	Timezone resolution when needed for local solar calculations.	When timezone cannot be resolved locally or needs confirmation.
`services.swpc.noaa.gov`	Standard web request metadata	Solar flare and space-weather data.	When the solar flare feature refreshes live data.
`Google AdMob`	Device and usage signals AdMob needs to serve and measure one ad (no advertising identifier; we request non-personalised ads)	Load the single optional rewarded video that unlocks the free trial.	Only if you choose to watch the rewarded trial video. If you never tap it, the ad SDK is never started and no request is made.

These providers may receive normal internet request information such as IP address, user agent, timestamps, or request metadata. Their handling of that information is governed by their own policies:

4. Health and wellness data

Chronosync Plus may contain information that feels health-related, including sleep timing, light exposure, skin type, estimated vitamin D production, estimated burn-time, and UV context. We treat this as sensitive personal information. The app is designed so this information remains on your device unless you intentionally export, share, back up, screenshot, or otherwise disclose it.

The app does not diagnose, treat, cure, prevent, monitor, or manage any disease or medical condition. We do not use your local wellness data to make automated decisions about insurance, employment, credit, medical eligibility, or similar rights.

5. Permissions

Permission	Why it is requested	What happens if you deny it
Location	To calculate sunrise, solar noon, sunset, sun position, UV context, weather, and vitamin D windows for your selected area.	You can use manual location entry where available, but location-based estimates may be less convenient or unavailable.
Notifications	To deliver local reminders for sunrise, solar noon, sunset, and blue-blocking glasses.	The app can still display information while open, but lock-screen reminders will not appear.
Camera	To estimate ambient brightness for the Lux Meter when a hardware ambient-light reading is not available.	Lux Meter features may be unavailable or less accurate. Camera frames are not recorded, saved, or transmitted.

6. Information we do not collect

No Chronosync account registration, email login, or password is required.
No use of the advertising identifier (IDFA), no IDFA-based tracking, and no cross-app tracking. The optional AdMob rewarded video (section 3) runs non-personalised.
No analytics SDK, behavioral event tracking, heatmaps, or session replay.
No sale or sharing of personal information for advertising.
No contacts, microphone, calendar, photos library, or Apple Health access unless a future version clearly asks for a separate permission.
No records of which third-party apps you use.

7. Local notifications and Shortcuts

Solar alarms and glasses reminders are scheduled locally through iOS notification features. Native Shortcuts actions may open the app or navigate to app screens. We do not receive a server callback when a local notification fires or when you run a local Shortcut.

8. Exports, backups, and user sharing

If you export data, back up your device, share screenshots, send logs to support, or manually copy information out of the app, that action may disclose your information outside Chronosync Plus. Review exported files and screenshots before sharing them.

9. Children

Chronosync Plus is intended for adults. It is not directed to children under 13, and we do not knowingly collect personal information from children under 13. If you believe a child has provided personal information to us, contact us so we can respond appropriately.

10. Data retention and deletion

Local app data remains on your device until you delete it, reset the app, uninstall the app, or overwrite it. See our Data Deletion page for steps. We do not maintain a central account database to delete.

11. Security

We use reasonable technical and organizational measures appropriate for a local-first app, but no app, device, network, or storage method can be guaranteed to be perfectly secure. Keep iOS updated, use a strong device passcode, and avoid sharing exported files with people you do not trust.

12. International users

Third-party data providers may process requests in jurisdictions outside your location. By using features that contact those providers, you understand that request metadata may be processed according to their policies and applicable laws.

13. Changes to this policy

We may update this Privacy Policy as the app changes. Material changes will be reflected by updating the effective date and, when appropriate, through in-app notice.

14. Contact

Email: support@chronosyncplus.com