1. Who we are and what the App is

Tetragen 3D is an educational app for exploring 3D geometry (visualizations, properties, lessons, and related tools). We do not require you to create an account. The current version does not show third-party advertising.

2. Information stored on your device

To make the App work, we may store data only on your device (for example with Android DataStore), including:

• Language and appearance (theme / light–dark mode)
• Laboratory / 3D viewer preferences (aids, units, backdrop, and similar options)
• Lesson progress and scores, if you use Lessons
• Onboarding and similar local flags

This information stays on the device unless you clear the App’s storage, uninstall the App, or voluntarily share something outside the App (for example a screenshot).

3. Network use and Google Firebase

Core learning features are designed to work without a network connection. When a network is available, the App may use the Internet for limited purposes:

• Stability: Google Firebase Crashlytics, to detect and fix crashes and serious errors. Technical data may include device model, OS version, App version, and crash/stack information.
• Firebase platform components: Firebase Analytics may be included as part of the Firebase SDK stack used with Crashlytics. We do not use it to show ads or to build advertising profiles for third-party ads.
• App updates: Google Play in-app update checks so you can learn when an update is available (non-blocking / flexible flow).

We configure the App so that advertising ID (AD_ID) collection is disabled for this product.

4. What we do not do

We do not sell your personal information. We do not ask for your name, email, contacts, photos, or precise location as a condition of using the App. We do not use the App to display third-party ads in the current version.

5. Children

The App is a general educational product. We do not knowingly collect personal information from children beyond the technical diagnostics described above. If you are a parent or guardian and believe a child provided information inappropriately, contact us through the store listing and we will take reasonable steps to delete it where applicable.

6. Sharing

Diagnostic data may be processed by Google on our behalf as the provider of Firebase / Google Play services, under Google’s terms and privacy notices for those services. We do not sell that data. We may disclose information if required by law or to protect users, the App, or our legal rights.

7. Retention

Local preferences and progress remain until you clear storage or uninstall. Crash reports and related diagnostics retained in Firebase follow Google Firebase retention practices.

8. Your choices

You can:

• Change language and many preferences inside Settings
• Clear App storage or uninstall to remove local data
• Restrict network access on the device (this may stop crash uploads and update checks; core offline features should still work)
• Leave feedback or ratings only if you choose to, via Google Play (we do not force ratings)

9. Data safety disclosures

When you install from Google Play, also review the Data safety section on the store listing for com.tetrahedron.cubo3d. That section summarizes collection practices for Play users and should be read together with this policy.

10. Contact

Privacy questions: use the developer contact on our Contact or the Google Play listing for package com.tetrahedron.cubo3d.

11. Changes

We may update this policy. The “Last updated” date above will change when we do. Continued use after an update means you accept the revised policy. If you disagree, stop using the App and uninstall it.