Privacy Policy

This policy explains what data GrindLab ("the app", "we") handles and how. It is written in plain language. If something is unclear, please email us at the address at the bottom.

1. Who we are

GrindLab is published by Nathan King. You can reach us at the email address in the Contact section below.

For the purposes of the EU General Data Protection Regulation (GDPR) and the UK GDPR, Nathan King is the data controller for any personal data processed in connection with GrindLab.

2. What data the app handles

2.1 Photos you capture or import

When you take a photo with the in-app camera, or import a photo from your photo library, the image is processed on your device using Apple's Vision framework. The app extracts particle measurements and discards the rest. The original image (or a compressed thumbnail) is stored locally on your device so it appears in your analysis history.

• Photos are not uploaded to any GrindLab server. GrindLab has no server.
• Photos are not sent to any external service.
• Photos remain on your device until you delete them in the app's History view or uninstall the app.

2.2 Analysis history and settings

The app stores the following on your device:

• Particle analysis results (median size, uniformity score, distribution statistics, etc.)
• Brew journal entries you create (beans, recipe parameters, tasting notes, ratings)
• Calibration values
• App settings (analysis mode, target ranges, preferences)
• A locally generated identifier for each analysis and journal entry (used only to tell entries apart)

This data is kept in a local database inside your app sandbox. It is included in your iCloud device backup if you have iCloud Backup enabled for GrindLab — that backup is managed by Apple under Apple's privacy policy and is not visible to us.

Analysis history is kept until you delete it. The brew journal keeps your 200 most recent entries; older entries are removed automatically when you exceed that limit.

2.3 Camera and photo library permissions

The app asks for two iOS permissions:

• Camera access — to capture grind photos for analysis.
• Photo library access — only if you choose to import a photo from your library for analysis, or to save an analysis image to your photos from the share sheet.

You can revoke either permission at any time in iOS Settings → GrindLab. The app will continue to function for any features that do not require the revoked permission.

3. What we do not collect

We want to be specific about this:

• No account, email address, name, or password (the app has no sign-in).
• No advertising identifier (IDFA).
• No analytics or crash-reporting SDKs of any kind.
• No location data.
• No contacts, calendar, microphone, or health data.
• No tracking across apps or websites. The app's privacy manifest declares NSPrivacyTracking = false.

4. Third-party services

GrindLab does not connect with any third-party services.

5. How we use data

We use the data described in section 2 solely to:

• Run the grind analysis you requested.
• Display your analysis history, brew journal, and comparisons.
• Apply the settings and calibration you've configured.

We do not use your data to build profiles, train models, sell to third parties, or for any advertising purpose.

6. Data retention and deletion

Because all of your data lives on your device, you control retention:

• Delete individual analyses from the History view.
• Delete your brew journal entries from the Brew Journal view.
• Reset all settings from Settings → Reset All Settings.
• Delete everything by uninstalling the app. Uninstalling removes all locally stored data (subject to iCloud Backup behavior controlled by you and Apple).

We have no server, so there is nothing for us to delete on our side.

7. Children's privacy

GrindLab is not directed to children under 13. The app does not knowingly collect personal information from children. If you believe a child has provided personal information to us, please contact us so we can address it (although in practice the app does not transmit personal information off-device).

8. Changes to this policy

If we change this policy, we will update the "Last updated" date at the top and, for material changes, note the change in the app's release notes. Continued use of the app after a change constitutes acceptance of the updated policy.

9. Contact

Questions or requests related to your privacy?

Email: [email protected]

If you are in the EU/UK and believe your data protection rights have been infringed, you also have the right to lodge a complaint with your local supervisory authority.

GrindLab is an independent app and is not affiliated with Apple or any coffee equipment manufacturer.