Privacy policy

Last updated: 19 October 2026

Zenigo is built so that your data stays on your device. The app works entirely in your browser: camera images, your location and motion sensor data are processed locally and are never sent to us or to anyone else. This policy explains the little data that is processed anyway.

Controller

Hosting

This website and the app are delivered by Cloudflare, Inc., 101 Townsend St., San Francisco, CA 94107, USA (content delivery network and protection against attacks). When you open a page, Cloudflare necessarily processes technical connection data:

• IP address
• date and time of the request
• requested page or file
• browser and operating system (user agent)
• referring page (referrer)

This data is needed to deliver the website securely and reliably. The legal basis is Art. 6(1)(f) GDPR (legitimate interest in a secure, working website). We have concluded a data processing agreement with Cloudflare. Cloudflare is certified under the EU-U.S. Data Privacy Framework; transfers to the USA are based on the adequacy decision of the European Commission (Art. 45 GDPR). We do not evaluate this data and do not combine it with other data.

What the app processes on your device

Camera and photos

When you start the camera or choose a photo, the image is analysed in your browser to find the stars in it. Images are not stored and not uploaded. The camera only runs while you have it switched on, and only after you have allowed access.

Location

The app needs your approximate position to convert star positions into directions for your telescope. You can enter it by hand or let the browser determine it (the “GPS” button in Settings), which asks for your permission first. The position is only stored on your device.

Motion sensors and compass

If you turn on “Align”, the app reads the orientation sensors of your device to move the map with the phone. This data is processed in the moment and not stored, except for a compass correction you choose to save.

Observing list and logbook

Your observing list and logbook entries (object, date and time, eyepiece, altitude, Moon, the coordinates of your site and your notes) are stored in your browser’s local storage only. They are not uploaded. An export creates a file on your device; what happens with it is up to you.

Satellites

When you are online and satellites are switched on in the map filter, the app loads the current orbital elements of the ISS and other bright satellites from our own server (zenigo.app), which gets them from CelesTrak (celestrak.org). No location or other personal data is sent with this request; it is an ordinary page request handled by Cloudflare as described under Hosting. The positions are calculated on your device. The orbital elements are not stored, so satellites are not shown offline.

Settings stored on your device

Your settings (location, pointing mode, chosen camera, camera field of view, eyepiece point, compass correction, map filter, chosen target and display options) are saved in your browser’s local storage, so they are still there next time. For offline use the browser also keeps a copy of the app (service worker cache). This data never leaves your device. You can delete it at any time by clearing the website data for Zenigo in your browser settings.

No cookies, no tracking

Zenigo sets no cookies, uses no analytics or advertising services and has no social media plugins. Fonts are delivered from our own server, not from third-party providers.

Links to other websites

The object details in the app link to external sources (SEDS Messier Database, In-The-Sky.org, NASA, SIMBAD and Wikipedia), and the menu links to location-based services (meteoblue for seeing and clouds, lightpollutionmap.info for light pollution, Heavens-Above for satellite passes). These links contain the coordinates of your location, rounded to about 100 m, so the provider can show the information for it. These sites are only contacted when you tap a link. From then on, the privacy policy of the respective provider applies.

Contact by email

If you write to us, we use your email address and the content of your message only to answer your inquiry. The legal basis is Art. 6(1)(f) GDPR, or Art. 6(1)(b) GDPR if your inquiry concerns a contract. We delete the messages when they are no longer needed, unless legal retention periods apply.

Your rights

Under the GDPR you have the right to:

• access the personal data we hold about you (Art. 15),
• have incorrect data corrected (Art. 16),
• have your data deleted (Art. 17),
• restrict processing (Art. 18),
• receive your data in a portable format (Art. 20),
• object to processing based on legitimate interest (Art. 21).

To exercise these rights, email zenigo@christianranz.com. You also have the right to lodge a complaint with a data protection supervisory authority, for example the State Commissioner for Data Protection and Freedom of Information Baden-Württemberg (Landesbeauftragter für den Datenschutz und die Informationsfreiheit Baden-Württemberg).

Changes

If the app or the legal situation changes, we will update this policy. The current version is always available on this page.