Effective: 1 October 2026
1. Controller
Oliver Kröner
Ziegelei 5
73765 Neuhausen auf den Fildern, Germany
Email: privacy@kroener.digital
Phone: +49 7158 9809940
2. What the app does
The app shows a digital business card as a QR code. The card is maintained in the “Visitenkarte” web application and transferred to the device by scanning a pairing QR code. The app then works offline from a local copy and contacts the server only when you pull the card down to refresh it.
The app contains no advertising, no analytics or tracking tools and no third-party crash reporting.
3. Data processed
| Data | Purpose | Where it goes |
|---|---|---|
| Camera image while scanning the pairing code | Reading the QR code | On the device only. No images are stored or sent. |
| Pairing data from the QR code (server address, organisation, one-time pairing secret) | Pairing the device | To the server named in the QR code |
| Device name (manufacturer and model), platform (Android/iOS), app version | So you and your organisation can recognise paired devices and revoke them individually | To that server |
| Device ID, device token and short-lived access token | Authenticating the device when the card is refreshed | Issued by the server, stored encrypted on the device (Android Keystore / iOS Keychain) |
| Your card's content (name, role, contact details, links, photo, logo) | Displaying the card and generating its QR codes | Downloaded from the server and stored locally |
All connections are encrypted with TLS (HTTPS). The app excludes its data from cloud backups and device-to-device transfer.
4. Legal basis
Art. 6(1)(b) GDPR (providing the business card service you or your organisation use) and Art. 6(1)(f) GDPR (legitimate interest in secure operation, in particular revoking individual devices). Camera access happens only after you grant it through the operating system's permission prompt.
5. Recipients
Data goes only to the server whose address is in the scanned pairing code. If your organisation uses the Visitenkarte application operated by Kröner Digital, Kröner Digital processes the data on your organisation's behalf, and your organisation is the controller for the card's content. If your organisation runs its own server, its privacy notice applies. The app does not pass data to any other third party or transfer it outside the EU/EEA.
6. Retention and deletion
The local copy and credentials stay on the device until you unpair it, clear the app's data or uninstall the app. If the device is revoked in the web application, the app discards its credentials on the next refresh. You or your organisation can delete the device record on the server in the web application.
To have your data deleted, email privacy@kroener.digital.
7. Your rights
You have the right of access, rectification, erasure, restriction, data portability and objection (Art. 15–18, 20, 21 GDPR), and the right to lodge a complaint with a supervisory authority, such as the State Commissioner for Data Protection and Freedom of Information of Baden-Württemberg.
8. Children
The app is intended for professionals, not for children under 16.
9. Changes
If the processing changes, this page will be updated. The version published here applies.
This is a translation of the German privacy policy. In case of doubt, the German version at /de/datenschutzerklaerung/visitenkarte-app governs.