Effective date: October 3, 2026
The short version: Materia Medica keeps your herbs, recipes, batches, remedies, photos and settings on your device. We never receive them. The app has no account, no ads, no analytics and no tracking, and it does not use the internet.
We do not collect any personal information. Materia Medica does not require an account, and everything you enter (herbs, recipes, batches, remedies, notes, photos and settings) is stored only in the app's private storage on your device. We, the developer, never see it, because the app has no way to send it to us.
The app does not request internet access and does not connect to any server.
When you add a photo, import a file or restore a backup, you choose it through Android's own picker, which gives the app access to only the item you pick. The app copies chosen photos into its private storage. It does not read your other photos or files. If you pick a photo from Google Drive, the transfer happens through Android's picker and Google's service, under Google's privacy policy.
The app lets you share herbs, recipes, remedies or your whole collection as a file, and create a backup file, using Android's standard share sheet and file picker. This is entirely your choice: you decide where a file goes, and the app never sends one on its own. Shared files and plain backups are not encrypted, so anyone who has one can read it; think before you share one. You can protect a backup with a passphrase: the file is then encrypted on your device and the passphrase is never stored or sent anywhere, so a forgotten passphrase cannot be recovered by anyone. Files you receive from other people are not verified, so review imported data before relying on it.
The app can print an herb entry, or several, using Android's standard print screen. The app only builds a PDF of the pages you choose on your device and hands it to Android; it never sends it anywhere itself. What happens next depends on the printer or print service you pick on that screen. A printer on your network receives the document directly, and a cloud or manufacturer print service (for example one installed by your printer's maker, or a Google account's cloud printing) may send it over the internet and is governed by that service's own privacy policy. "Save as PDF" keeps the file on your device, where you choose. Printed pages contain whatever you chose to include, such as your notes, photos, journal entries, recipes and remedies, so think about where it goes.
If you turn on batch reminders, the app asks for notification permission and schedules local notifications on your device. They are not sent through any server.
Android may include this app's data in your Google account backup if backup is turned on in your device's settings. That is controlled by your device and your Google account, not by Materia Medica, and is governed by Google's privacy policy. You can turn it off in your device's settings.
Materia Medica requests only these permissions:
It does not request access to your contacts, location, microphone or internet, and it contains no advertising, analytics or crash-reporting software. The camera is used through Android's camera screen when you choose to take a photo.
Because your data is only on your device, you control it. You can delete any entry in the app, and uninstalling the app removes everything it stored. Backup and shared files you saved yourself stay where you saved them until you delete them.
Materia Medica is not directed at children under 13. We do not knowingly collect personal information from anyone of any age; the app does not collect personal information at all, as described above.
If this policy changes, this page will be updated with a new effective date, and any material change affecting how your data is handled will be described here.
Questions about this policy or Materia Medica can be sent to apps@katr.com.