Privacy Policy

Effective date: March 8, 2026

1. Image Processing

All image capture, alignment, and focus stacking is performed entirely on your device using the GPU (Metal compute shaders). Your photos are never uploaded to any server. The processed results are saved to your device's photo library only when you choose to save them.

2. Anonymous Analytics & Crash Reporting

Zeus Focus Stacking uses Firebase Analytics and Firebase Crashlytics (by Google) to collect anonymous usage data. This helps us understand how the app is used and fix crashes quickly. The data collected includes:

• App events (e.g., capture started, stacking completed, gallery opened)
• Processing performance metrics (stacking time, frame count, resolution)
• Device model and iOS version (anonymous, not linked to identity)
• Crash reports and error logs
• Session frequency and duration

This data is not linked to your identity. We do not collect:

• Photos or images
• Personal information (name, email, phone number)
• Advertising identifiers (IDFA)
• Location data transmitted to servers
• Content of your stacking projects

Firebase Analytics data is stored on Google's servers and is subject to Google's Privacy Policy.

3. Location Data

If you grant location permission, Zeus Focus Stacking saves the GPS coordinates of your capture sessions locally on your device using SwiftData. This allows you to browse your stacking projects on a map within the app. Location data is never transmitted to any external server or third party.

Location access is optional. The app functions fully without it.

4. Lens Breathing Calibration Data

Zeus Focus Stacking may download lens calibration profiles from Firebase Cloud Storage to improve alignment accuracy. This is a one-way download:

• The app downloads pre-computed calibration data for your lens model
• No user data, device information, or photos are sent to the server
• Downloaded calibration data is cached locally in the app's storage
• The Firebase project used is zeus-calibration

5. Camera and Photo Library Access

Zeus Focus Stacking requests access to:

• Camera — to capture focus-bracketed images for stacking
• Photo Library (write) — to save your stacked results
• Location (optional) — to geotag your stacking projects locally

These permissions are used solely for in-app functionality. No data from these sources is transmitted externally.

6. Third-Party Services

Zeus Focus Stacking uses the following third-party services:

• Firebase Analytics — anonymous usage analytics (see Section 2)
• Firebase Crashlytics — crash reporting (see Section 2)
• Firebase Cloud Storage — lens calibration data downloads (see Section 4)

No advertising SDKs or tracking services are integrated.

7. User Accounts

Zeus Focus Stacking does not require or support user accounts. There is no sign-up, login, or authentication of any kind.

8. In-App Purchases

Purchase transactions are handled entirely by Apple through the App Store. Zeus Focus Stacking does not process, store, or have access to any payment information.

9. Children's Privacy

Zeus Focus Stacking does not knowingly collect personal data from children or any other users. The anonymous analytics data collected is not linked to any individual identity and complies with COPPA and similar regulations.

10. Data Security

All your images and project data remain on your device, protected by iOS's built-in security features including device encryption and app sandboxing. Anonymous analytics data is transmitted securely to Firebase servers using HTTPS encryption.

11. Changes to This Policy

If we make changes to this privacy policy, we will update the effective date at the top of this page. Material changes will be communicated through an app update.

12. Contact

If you have questions about this privacy policy, contact us at:

privacy@zeusfocusstacking.com