Kartesio

Privacy Policy

Last updated: 8 August 2026

In short: Kartesio does not ask for your name, email or location. Photos of exercises are sent for processing and are not stored by us. Your history stays on your phone.

1. Who is responsible

The data controller for Kartesio is its developer. For any privacy question or request, please use the contact form.

2. What we process

2.1 Photos of exercises

When you photograph an exercise, the cropped image is sent to Google Gemini for recognition and to our server for processing. The image is not stored on our servers: it is transmitted, processed and discarded. It is never associated with your identity, because we do not have one.

2.2 Device identifier

On first launch the app generates a random identifier (UUID) stored on your device. It counts your available scans and prevents abuse. It is not derived from any hardware identifier and cannot be traced back to you. Uninstalling the app deletes it permanently.

2.3 Advertising identifier

Google AdMob uses the Android advertising ID to serve ads and to verify that a rewarded video was actually watched. You can reset or limit it at any time in your device settings, under Google › Ads.

2.4 Settings and history

Country, school level and your solved exercises are stored only on your device and never transmitted to us. The history holds up to 200 entries; older ones are deleted automatically.

3. What we do not process

We do not collect your name, email address, phone number, contacts, location, or any account information. Kartesio has no login.

4. Third parties

ServicePurposePolicy
Google Gemini API Reads the exercise and produces the explanation Terms
Google AdMob Serves ads and verifies rewarded videos Privacy
Cloudflare Hosts the server that processes the requests Privacy
Web3Forms Delivers messages sent through the contact form Privacy

5. Legal basis and retention

Processing rests on our legitimate interest in providing the service you asked for (Art. 6(1)(f) GDPR) and, for personalised advertising, on your consent, which you can withdraw at any time from your device settings.

Solved exercises are cached on our server for up to 90 days to avoid recomputing the same problem, in a form that contains only the mathematics — no image, no identifier. Credit counters reset daily.

6. Your rights

Under the GDPR you may request access, rectification, erasure, restriction, portability, and object to processing. Since we hold no personal data that identifies you, most requests are satisfied simply by uninstalling the app, which removes the device identifier, the settings and the history. For anything else, write to us through the contact form.

You also have the right to lodge a complaint with your national data protection authority.

7. Children

Kartesio is intended for students aged 13 and over. We do not knowingly process data from children under 13. If you believe a child has used the app, contact us and we will act accordingly.

8. Changes

We may update this policy. The date at the top always reflects the current version.