1. Eligibility and acceptance

You must be able to form a binding agreement under the laws that apply to you. If you are a minor, a parent or guardian should review these Terms and supervise use of the App.

2. License to use the App

We grant you a personal, limited, non-exclusive, non-transferable, revocable license to install and use the App for educational and personal purposes on devices you own or control. You may not sell, rent, sublicense, or publicly redistribute the App except as allowed by Google Play or mandatory law.

3. Educational purpose — important disclaimer

The App offers geometry visualizations, approximate measures, formulas, lessons, and related learning aids. It is not professional engineering, architecture, surveying, manufacturing, exam accreditation, or legal advice. Meshes and numeric results may be approximate or rounded. You are responsible for how you use the information. Do not rely on the App alone for exams, grades, construction, manufacturing, or safety-critical decisions.

4. Acceptable use

You agree not to:

• Use the App for unlawful purposes
• Reverse engineer, decompile, or modify the App except where mandatory law allows
• Scrape or extract content or assets to build a competing product in bad faith
• Misrepresent the App as official school, exam-board, or Google accreditation
• Interfere with the App’s normal operation or with other users’ devices
• Abuse rating, review, or update mechanisms on Google Play

5. Performance and your device

Interactive 3D can use significant CPU/GPU, battery, and heat. Results depend on your hardware, OS, drivers, and thermal state. To the maximum extent permitted by law, we are not responsible for battery drain, heating, reduced performance, or device wear from using the App.

6. Offline features, network services, and updates

Core educational features are designed to work offline. When a network is available, the App may contact Google services for crash diagnostics (Firebase Crashlytics) and Play in-app update checks, as described in the Privacy Policy. We may release updates, change or remove features, or discontinue the App. We do not guarantee uninterrupted service or that every device will receive every update. Flexible updates are optional and do not block basic use of the App.

7. No account; local data

The App does not require an account. Preferences and progress may be stored only on your device. You are responsible for managing that data (including clearing storage or uninstalling). We are not obligated to recover local data after loss, wipe, or uninstall.

8. Intellectual property

The App name “Tetragen 3D”, branding, UI, and original content are protected by applicable law and belong to their respective owners. Open-source libraries (including Filament and SceneView) remain under their own licenses (see Open-source licenses in the App). These Terms do not transfer ownership of any IP to you.

9. Google Play and other third parties

Distribution, payments (if any), ratings, and refunds are handled under Google Play’s terms. Google Firebase and device OS services have their own terms. We are not responsible for store policies, OS behavior, or third-party outages outside our reasonable control.

10. Disclaimer of warranties

THE APP IS PROVIDED “AS IS” AND “AS AVAILABLE,” WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT, TO THE MAXIMUM EXTENT PERMITTED BY LAW. We do not warrant that the App will be error-free or that every formula or measure will fit every academic or professional use.

11. Limitation of liability

To the maximum extent permitted by law, we and our contributors are not liable for indirect, incidental, special, consequential, or punitive damages, or for loss of data, grades, time, profits, or device value, arising from use of or inability to use the App. Our total liability for claims relating to the App shall not exceed the amount you paid for the App (via Google Play) in the twelve (12) months before the claim, or zero if the App was free.

12. Termination

Your license ends if you breach these Terms. We may stop providing the App or features. Provisions that should survive (including IP, disclaimers, and liability limits) remain in effect.

13. Changes to these Terms

We may update these Terms. The “Last updated” date will change when we do. Continued use after changes means acceptance. If you disagree, stop using the App and uninstall it.

14. Severability

If any part of these Terms is unenforceable, the rest remains in effect.

15. Contact

Questions about these Terms: use the developer contact on our Contact or the Google Play listing for package com.tetrahedron.cubo3d.