Master Clock — Privacy Policy

Last updated: 27 June 2025

Master Clock is a GPS-disciplined navigation instrument for iPhone. This policy explains what data the app uses, and what it does not do with it.

Data collected and how it is used

Master Clock uses your device's GPS and magnetometer to display time, position, speed, course and heading. When you start a logging session, the app writes position entries to a local file on your device at your chosen interval.

• All data stays on your device. No location data, log entries, or any other personal information is ever transmitted to any server operated by the developer.
• Log files are excluded from iCloud backup so they are never automatically uploaded to Apple's servers.
• Export is user-initiated. If you choose to export a log via the share sheet, you control where it goes. The app does not send it anywhere automatically.
• NTP time checks are made periodically to cross-check your device clock. These requests go to public time servers (pool.ntp.org, time.apple.com, time.cloudflare.com) and contain no location data or user-identifying information.

App preferences

The app stores your settings (units, colour scheme, speed range, log interval) in UserDefaults on your device. This data never leaves your device.

Third-party SDKs and analytics

Master Clock contains no third-party analytics, advertising, or crash-reporting SDKs. There is no tracking of any kind.

Background location

The app requests "Always On" location permission so that GPS time and interval logging continue when the screen is off — for example, during a passage when the phone is pocketed. This permission is used solely to operate the app's core navigation functions. Location data is never transmitted off the device.

Children's privacy

Master Clock does not collect any personal data from any user, including children.

Changes to this policy

If the privacy practices of the app change in a future update, this page will be updated to reflect them.

Contact

If you have any questions about this privacy policy, please contact: owens.d@icloud.com