Privacy & User Policy

Last updated: July 13, 2026

This Privacy & User Policy ("Policy") explains how App ("we", "us", or the "Developer") handles information across all applications published by the Developer (each, the "App"). By downloading or using any App, you agree to this Policy. If you do not agree, do not use the App.

This Policy applies to all of the Developer's applications. Not every category of data described below is collected by every App; each App collects only the information relevant to the features you use.

1. Eligibility

You must be of the legal age required to form a binding agreement in your jurisdiction, or have the consent of a parent or legal guardian, to use the App.

2. Information We Collect

To operate the App, we may collect information including, but not limited to:

3. How We Use and Share Information

We use this information to provide, secure, maintain, and improve the App and to manage subscriptions. We share information with service providers acting on our behalf (including RevenueCat and Google), with app stores and payment processors, and where required by law or to protect our rights. We do not sell your personal information for money; sharing data with analytics or advertising providers may be considered "sharing" under certain US state laws, and you may opt out by contacting us.

4. Third-Party Services

The App relies on third-party services, including Apple, Google, and RevenueCat. Information handled by these services is governed by their own privacy policies, and we are not responsible for their practices. We encourage you to review them.

5. Apple Health (HealthKit) Data

Trace can, only with your explicit permission, read data from Apple Health (HealthKit) so you can bring your existing outdoor activities into your Trace trip history.

What we access. When you tap "Import from Apple Health" and grant access on the iOS permission screen, Trace reads your workouts — runs, walks, hikes, and rides — and each workout's route (the GPS path recorded with it). Trace requests read-only access. It never writes, changes, or deletes anything in Apple Health, and it does not request permission to do so. You choose which categories to allow on Apple's own permission screen, and you can change or revoke this at any time in iOS Settings → Privacy & Security → Health → Trace.

How we use it. Imported workouts and their routes are converted, entirely on your device, into trips in your Trace history — mapped and measured alongside the trips you record directly in Trace. On the free tier you can import workouts from the last 30 days; Trace Pro lets you reach further back into your history. That is the only use of this data.

How it is stored and shared. Health and workout data — and any trip created from it — is processed and stored only on your device. It is never transmitted to us (we operate no servers) and is never sold, shared, or disclosed to any third party. In particular, Apple Health data is never used for advertising or marketing, is never used for any data-mining or profiling purpose, and is never sent to any analytics, advertising, or other third-party service, including any services named elsewhere in this Policy. If — and only if — you turn on iCloud sync, trips (including those imported from Apple Health) sync to your own private iCloud account through Apple; they remain accessible only to you, and we cannot read them.

Your control. Importing from Apple Health is entirely optional and off until you start it. You can decline it, import once and never again, delete any imported trip from within Trace, or revoke Trace's Health access at any time in iOS Settings — none of which affects your data in Apple Health itself.

Our use of Apple Health data follows Apple's HealthKit requirements and is limited to providing and improving the trip-tracking features described above.

6. Data Retention and Security

We retain personal information only as long as necessary for the purposes described in this Policy or as required by law. We use reasonable measures to protect your information, but no method of transmission or storage is completely secure, and we cannot guarantee absolute security.

7. Your Choices and Rights

You can enable or disable location and reset your advertising identifier at any time in your device settings; disabling location will limit the App's features. Subject to applicable law, you may request access to, correction of, or deletion of your information, or opt out of sharing, by contacting us at df@dukefu.com.

8. Acceptable Use and Tracking Other People

You agree to use the App only for lawful purposes. If the App lets you view another person's or device's location, you are solely responsible for obtaining that person's informed consent and for complying with all applicable laws. The App may not be used for stalking, harassment, surveillance without consent, or any unlawful purpose. You are solely responsible for how you use any information obtained through the App.

9. No Reliance for Safety-Critical Use

The App, and any location data it provides, may be inaccurate, delayed, or unavailable. The App is not intended for emergency, navigation, medical, law-enforcement, or other safety-critical use. You must not rely on the App in any situation where inaccurate or unavailable data could result in injury, death, or property damage.

10. Children

The App is not intended for children under 13 (or the minimum age required in your country), and we do not knowingly collect their information. If you believe a child has provided us information, contact us and we will delete it.

11. International Transfers

Your information may be processed in the United States and other countries where our service providers operate.

12. Disclaimers and Limitation of Liability

The App is provided "as is" and "as available," without warranties of any kind, express or implied, including as to accuracy, reliability, availability, or fitness for a particular purpose. To the maximum extent permitted by law, we will not be liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of data, profits, or damage to devices, arising from your use of or inability to use the App. To the maximum extent permitted by law, our total liability for any claim relating to the App will not exceed the greater of (a) the amount you paid us for the App in the 12 months before the claim, or (b) USD 50. We may modify or discontinue the App at any time. Nothing in this Policy excludes or limits liability that cannot be excluded or limited under applicable law, including your non-waivable rights as a consumer.

13. Indemnification

To the maximum extent permitted by law, you agree to indemnify and hold harmless Minghao Fu from any claims, damages, losses, or expenses (including reasonable legal fees) arising out of your use of the App, your violation of this Policy, or your violation of any law or the rights of any third party, including any person whose location you track.

14. Governing Law

This Policy is governed by the laws of United States, without regard to its conflict-of-laws rules, except where mandatory local consumer-protection law applies to you.

15. Severability

If any provision of this Policy is found to be unenforceable, the remaining provisions will continue in full force and effect.

16. Changes and Contact

We may update this Policy at any time, and changes may take effect immediately and without prior notice. The most current version is always the one published at https://www.dukefu.com/privacy-policy, and that version governs your use of the App. Because changes may be posted only at that link, you should review it periodically; your continued use of the App after a change is posted constitutes acceptance of the updated Policy. Where applicable law requires notice of, or your consent to, material changes, we will provide it. Questions: df@dukefu.com.