Privacy Policy — Günther (Reptile Feeding Calendar)
Last updated: 23 September 2026 (applies from version 1.8.0)
The short version
Günther keeps everything on your phone. The only exception is shared care, which you switch on yourself for one animal at a time. It lets two phones share that animal's records. Shared records are encrypted on your phone before they leave it, and only phones holding the sharing code can read them. The server that passes them between phones cannot. There are no accounts, no analytics and no advertising.
What the app stores on your phone
All of the following is saved in the app's private storage on your device:
- Your animals' names, species, life stage, body condition, weight, length and snout-vent length.
- Feeding records, notes, and recurring feed schedules.
- Weigh-ins, sheds, health checks, and reminders you set.
- UVB bulb install dates, parasite screening dates, and vet visit dates.
- Photos of your animal, if you add them. A copy is kept in the app's private storage so it cannot disappear when the system clears its cache.
- Your reminder preferences and reminder time.
If Android's own backup to your Google account is switched on for your phone, Android may include this app data in that backup, as it does for most apps. That backup belongs to your Google account; the app does not send it anywhere itself. The sharing codes described below are excluded from it.
Shared care (optional)
Shared care is off until you tap Start sharing for an animal, or join an animal someone shares with you.
What is shared: that animal's name, species, life stage, weight and length figures, feeding records and plan, weigh-ins, sheds, health checks, UVB, parasite and vet dates, and reminders set by hand.
What is never shared: photos, your reminder time and settings, your other animals, and anything about you or your phone.
How it works:
- Starting to share creates a random 256-bit key on your phone. It is shown as the sharing code (and as a QR code) for the other phone.
- Every record is encrypted on the phone with that key (XChaCha20-Poly1305) before it is sent over an encrypted HTTPS connection.
- The server stores only encrypted records under a random identifier derived from the key. It never receives the key. It cannot read names, foods, notes, dates, or which kind of record something is. It stores no account, no email address, no phone or device identifier, and no advertising identifier.
- The key is kept in your phone's secure storage (protected by the Android keystore). It is not included in the app's backup file or in Android's cloud backup.
Where the server is: the server runs on Cloudflare Workers, a hosting service. Its storage is restricted to Cloudflare's EU jurisdiction, so the encrypted records are stored in the European Union. Like any server on the internet, Cloudflare's network sees your phone's IP address when the app connects. The app's server code does not read, log or store IP addresses, and request logging is switched off.
How long it is kept: until sharing is stopped for both phones, which deletes everything stored for that animal on the server at once. A shared animal that neither phone has synced for over a year is deleted automatically.
Who can read it: anyone who has the sharing code. Only give it to people you look after the animal with. Stopping sharing on both phones makes the old code useless.
Scanning the code: on Android, the QR scanner is Google's code scanner in Google Play services. It runs on your phone, and Günther itself does not need camera permission for it.
Printing on a computer (optional)
Print on a computer sends one vet report from your phone to a browser you choose. The page on the computer shows a code; your phone scans it and encrypts the report for that one browser tab (X25519 key exchange and XChaCha20-Poly1305). Both screens show the same six-digit number so you can check you are sending to your own computer.
The server passes the report on without being able to read it. It deletes it the moment the computer has received it, and after 10 minutes at the latest. Nothing about you, your phone or the computer is stored. Closing the tab forgets the report.
Print from this phone uses Android's own print dialog and sends nothing to the app's server.
Reporting a problem
The app links to a Report a problem form on the same server. It is for reporting something written in a shared animal, a person you share with, a privacy concern or a bug. Using it is voluntary.
What is stored: the topic you choose, what you write, the time, and an email address only if you enter one to get a reply. Your IP address, your phone and your shared records are not stored with it, and the server cannot link a report to a shared animal.
Who reads it: only the app's developer. Where: Cloudflare's EU jurisdiction, like shared care. How long: until it has been dealt with, and at most 180 days, after which it is deleted automatically.
To stop receiving anything from someone you share with, you do not need to report them. Stop sharing → Only this phone cuts them off at once.
Permissions and why they are requested
| Permission | Why | When |
|---|---|---|
| Camera | To take a photo of your animal | Only when you choose to take a photo |
| Photo library | To pick a photo of your animal | Only when you tap the photo button; you pick the image |
| Notifications | Local reminders for feeding days, weigh-ins, health checks, parasite screening and your own reminders | Only when you switch reminders on |
| Internet | Shared care, if you use it | Only for animals you share |
All are optional. Reminders are created on your phone by the app itself. They are not push notifications, and no server sends them.
Analytics, tracking and advertising
There are none. No analytics SDK, no crash reporting, no advertising identifier, no third-party tracking of any kind.
Children
The app collects no personal data from anyone, including children. The report form stores only what a person chooses to write into it.
Deleting your data
Removing an animal in the app deletes its records from your phone. For a shared animal, this removes only your phone's copy. Stop sharing → Both phones deletes the shared copy from the server. Uninstalling the app deletes everything it stored on your phone.
Health disclaimer
Günther is a record-keeping and reminder tool for reptile keepers. It is not veterinary advice and does not diagnose illness. The husbandry information it displays is compiled from published sources, which are cited in the app's documentation. Always consult a qualified reptile veterinarian about your animal's health.
Changes to this policy
If the app gains any other feature that sends data, this policy will be updated before that feature ships, and the change will be described here.
Contact
Questions about this policy: guenther.app@proton.me