Privacy policy (Datenschutzerklärung)

1. Controller (Verantwortlicher)

The controller within the meaning of the General Data Protection Regulation (GDPR, Datenschutz-Grundverordnung, DSGVO) is:

endurancr is a free, non-commercial project by a private individual. No data protection officer has been appointed, as there is no legal obligation to do so.

2. This website

Hosting (Hosting durch Cloudflare Pages)

This website is a set of static files hosted on Cloudflare Pages, a service of Cloudflare, Inc., 101 Townsend St., San Francisco, CA 94107, USA ("Cloudflare"). Cloudflare acts as our processor (Auftragsverarbeiter) under Art. 28 GDPR, on the basis of Cloudflare's data processing addendum.

When you open this website, your browser necessarily sends technical data to Cloudflare's servers so the pages can be delivered. Cloudflare processes this data in server logs, in particular:

• your IP address,
• date and time of the request,
• the page or file requested and the amount of data transferred,
• the referring URL, if your browser sends one,
• browser type and version, operating system (user agent).

This data is processed to deliver the website, to keep it stable and secure, and to detect and fend off attacks such as denial-of-service attacks. The legal basis is Art. 6(1)(f) GDPR. Our legitimate interest is the secure and reliable delivery of this website. We do not combine this data with other data and do not use it to identify you. Logs are retained by Cloudflare only as long as needed for these purposes, according to Cloudflare's policies.

Cloudflare operates a global network, so data may be processed in the USA. Cloudflare is certified under the EU-US Data Privacy Framework, on the basis of the European Commission's adequacy decision under Art. 45 GDPR; in addition, Cloudflare relies on the EU Standard Contractual Clauses. More information: Cloudflare privacy policy, Cloudflare data processing addendum, Data Privacy Framework list.

No cookies, no analytics, no tracking

This website does not set cookies and does not store or read any information on your device (§ 25 TDDDG). There are no analytics, no tracking pixels, no advertising, no social media plugins, no external fonts and no embedded content from other sites. All files, including fonts, styles and images, are served from this domain.

External links

This website links to the Apple App Store, to kaessinger.com and to GitHub. Nothing is loaded from these services until you click a link. Once you follow a link, the privacy policy of the respective provider applies, for example the Apple privacy policy or the GitHub general privacy statement.

3. The endurancr app

endurancr is designed so that we never receive your data. The app has no user account, no server or backend, no analytics, no advertising and no third-party SDKs. We, the developer, have no access to any of the data described below.

• Training plan and settings. Your goal, plan and settings are stored only on your device.
• Apple Health. With your permission, the app reads workouts, workout routes, heart rate, resting heart rate, VO2 max, steps, running speed and running power from Apple Health, and saves your runs to Apple Health as standard workouts. This data never leaves your device through endurancr. It only leaves your device through Apple's own iCloud and Health sync, if you have enabled it, which is governed by Apple's privacy policy. You can grant or revoke each permission at any time in the Health app or in the iOS Settings.
• Location. With your permission, location is used only while you are recording a run, to measure distance and to record the route. It is not used in the background outside of a run and is not sent anywhere.
• iPhone and Apple Watch sync. Your plan and runs are synced directly between your iPhone and your Apple Watch using Apple's WatchConnectivity framework. While you record a run on Apple Watch, its live numbers (time, distance, pace, heart rate) are also sent to your iPhone through Apple Health's workout mirroring, to show them on the Lock Screen. No server of ours is involved.
• Backups and exports. A backup or export file is only created when you explicitly choose to create and share it, and it goes only where you send it, for example to the Files app or to another app of your choice.

Deleting the app removes the plan and settings stored by endurancr from your device. Workouts saved to Apple Health stay there until you delete them in the Health app.

Where the app processes data on your device on the basis of your permission, the legal basis is your consent (Art. 6(1)(a) and Art. 9(2)(a) GDPR for health data). You can withdraw your consent at any time with effect for the future (Art. 7(3) GDPR) by revoking the permission in the iOS Settings or the Health app.

4. Apple App Store

endurancr is distributed through the Apple App Store, run by Apple Distribution International Ltd. / Apple Inc. ("Apple"), which processes the data needed for this, such as your Apple Account and device information, as an independent controller. If you agreed on your device to share analytics with app developers, Apple gives us aggregated download and usage statistics and crash reports that do not identify you. We use this information only to fix bugs and improve the app. The legal basis is Art. 6(1)(f) GDPR, our legitimate interest in a stable app. For details see the Apple privacy policy.

5. Contacting us

If you contact us by email or phone, we process the details you provide (for example your email address, name and message) only to handle your request. The legal basis is Art. 6(1)(f) GDPR, our legitimate interest in answering you, or Art. 6(1)(b) GDPR if your request relates to entering into or performing a contract. We delete this data once your request has been dealt with, unless statutory retention obligations apply.

6. Your rights (Betroffenenrechte)

Under the GDPR you have the following rights regarding your personal data:

• the right of access (Art. 15 GDPR),
• the right to rectification (Art. 16 GDPR),
• the right to erasure (Art. 17 GDPR),
• the right to restriction of processing (Art. 18 GDPR),
• the right to data portability (Art. 20 GDPR),
• the right to withdraw consent at any time with effect for the future (Art. 7(3) GDPR).

Right to object (Widerspruchsrecht, Art. 21 GDPR). Where we process data on the basis of Art. 6(1)(f) GDPR, you have the right to object at any time, on grounds relating to your particular situation. We will then no longer process the data unless we can demonstrate compelling legitimate grounds that override your interests, rights and freedoms, or the processing serves the establishment, exercise or defence of legal claims.

To exercise your rights, simply write to [email protected]. Please note that we do not hold any app data about you, so for data inside the app or in Apple Health you can view, export and delete it yourself on your device at any time.

We do not use automated decision-making or profiling within the meaning of Art. 22 GDPR.

7. Right to lodge a complaint (Beschwerderecht bei einer Aufsichtsbehörde)

You have the right to lodge a complaint with a data protection supervisory authority (Art. 77 GDPR), in particular in the EU member state of your habitual residence, your place of work or the place of the alleged infringement. The supervisory authority responsible for us is:

Last updated: October 2026