Privacy policy / Datenschutz

This Privacy Policy explains how Kater Zerro ("we", "us", "our") processes personal data in connection with the Kater Zerro iOS application ("App") and the website at katerzerro.com ("Website"). It applies to users in the European Economic Area (including Germany), the United States, and all other regions.

Key facts at a glance

• The App processes all health data locally on your device. No health data is ever transmitted to our servers or any third party.
• We do not operate any backend infrastructure for the App.
• We do not sell, share, or use your data for advertising.
• We do not use cookies or tracking technologies on the Website.

Data controller

Data processed by the App

Apple HealthKit data (on-device only)

The App requests access to Apple HealthKit to provide its core features. The following data types are accessed:

All HealthKit data is processed exclusively on your device. It is never transmitted to our servers, shared with third parties, used for advertising or marketing purposes, or sold to data brokers. This is a technical requirement enforced by Apple's HealthKit framework and a firm commitment on our part.

You can revoke or adjust the App's HealthKit permissions at any time in iOS Settings → Privacy & Security → Health → Kater Zerro.

In-App Purchases

If you make a purchase within the App, the transaction is handled entirely by Apple Inc. through the App Store. We do not receive, process, or store your payment information. Please refer to Apple's Privacy Policy for details on how Apple handles transaction data.

No analytics, no crash reporting

The App does not include any analytics SDK, crash reporting service, or third-party tracking library. No usage data is collected from within the App.

Data processed by the Website

When you visit the Website, your web browser automatically transmits technical data to our hosting provider's servers, including your IP address, browser type and version, pages visited, and the date and time of access. This data is processed solely to ensure the technical availability of the Website and to detect and prevent misuse. We do not use this data to identify individual users and we do not place cookies or tracking technologies. Log data is deleted by the hosting provider after a short retention period in accordance with applicable law.

Legal basis for processing

HealthKit data — which includes health data as defined in Article 4(15) GDPR — constitutes a special category of personal data under Article 9 GDPR. We process this data on the legal basis of your explicit consent (Article 9(2)(a) GDPR in conjunction with Article 6(1)(a) GDPR). This consent is obtained through the iOS HealthKit permission dialog when you first use the App. You may withdraw your consent at any time by revoking HealthKit permissions in iOS Settings, without affecting the lawfulness of processing carried out before withdrawal.

Website access logs are processed on the basis of our legitimate interest in maintaining a technically functioning and secure website (Article 6(1)(f) GDPR).

Data retention

HealthKit data written by the App (alcohol consumption entries) is stored by Apple's HealthKit framework on your device, subject to your iOS settings and Apple's data management policies. You can view, edit, and delete this data at any time through the Apple Health app. We do not retain any App data on external servers.

Website access log data is retained by the hosting provider for the legally required minimum period.

Recipients and third parties

We do not share your personal data with any third parties for commercial purposes. The following technical parties are involved in operating the services:

• Apple Inc. — The App runs on Apple's iOS platform and uses Apple HealthKit and the App Store. Apple processes in-app purchase transactions and device/platform telemetry in accordance with Apple's Privacy Policy.
• Hosting provider — Our Website is hosted by a service provider who processes access log data as a data processor on our behalf.

There are no other data transfers, including no transfers to recipients outside the EEA.

Your rights under GDPR (EEA users)

If you are located in the European Economic Area, you have the following rights under the GDPR. Because all App data resides in Apple HealthKit on your device, most of these rights can be exercised directly through iOS Settings and the Apple Health app.

• Right of access (Art. 15 GDPR) — You can view all App-related health data at any time in the Apple Health app.
• Right to rectification (Art. 16 GDPR) — You can correct or edit health data entries directly in the App or in the Apple Health app.
• Right to erasure (Art. 17 GDPR) — You can delete individual alcohol entries in the App, or delete all App-related data in the Apple Health app. Uninstalling the App removes all App-specific settings from the device.
• Right to restriction of processing (Art. 18 GDPR) — You can restrict specific data types by adjusting HealthKit permissions in iOS Settings.
• Right to data portability (Art. 20 GDPR) — You can export your health data at any time through Apple Health app → Profile → Export All Health Data.
• Right to object (Art. 21 GDPR) — You can stop all processing by revoking HealthKit permissions at any time in iOS Settings.
• Right to withdraw consent (Art. 7(3) GDPR) — You can withdraw your HealthKit consent at any time in iOS Settings → Privacy & Security → Health → Kater Zerro without any detriment.

To exercise any of these rights, or if you have questions that cannot be answered by the above, please contact us at info@katerzerro.com.

Supervisory authority

If you believe your data protection rights have been violated and you are located in Germany, you have the right to lodge a complaint with the competent data protection supervisory authority:

If you are located in another EU member state, you may also contact the supervisory authority in your country of residence.

Your rights under CCPA (California residents)

If you are a California resident, the California Consumer Privacy Act (CCPA) provides you with specific rights regarding your personal information. We do not sell personal information. Because the App processes all data locally on your device, we do not collect, store, or share personal information on our systems. You may exercise any CCPA rights by contacting us at info@katerzerro.com. We will respond to verifiable requests within the timeframes required by applicable law.

Children's privacy

The App is not directed at children under the age of 16. We do not knowingly collect personal information from children under 16. If you believe a child under 16 has used the App and you have concerns, please contact us at info@katerzerro.com.

Links to other resources

The Website and App may contain links to external websites or services that are not operated by us. We are not responsible for the privacy practices of those websites. We encourage you to review the privacy policy of any external site you visit.

Note on health information

The App and Website do not provide medical advice. All information and analysis in the App is for informational and self-monitoring purposes only and does not constitute medical advice, diagnosis, or treatment. The App is not a medical device. Always consult a qualified healthcare professional regarding any questions about your health or your alcohol consumption.

Changes to this policy

We may update this Privacy Policy from time to time. When we do, we will revise the "last updated" date at the bottom of this page. For significant changes, we will provide notice within the App. Your continued use of the App or Website after the effective date of a revised policy constitutes acceptance of the changes.

Contact

If you have any questions, concerns, or requests regarding this Privacy Policy or the processing of your personal data, please contact us:

info@katerzerro.com