Privacy Policy

Last updated: November 2026

Matheion ("we", "our", or "the app") is a self-study computer science app and website. This policy explains what information the app and matheion.zlu.me use and how it is handled.

Summary

Your learning progress and quiz scores in the app are stored locally on your device. We do not sell your information. Matheion uses first-party anonymous product analytics on the website and in the app (described below). We do not use advertising identifiers or third-party ad trackers.

Information stored on your device

The app may store the following on your device:

• Units you have marked as practised or completed
• Best quiz scores per module
• App preferences via local storage (SharedPreferences)
• An anonymous install identifier used for first-party product analytics

Lesson content is bundled in the app. Progress stays on-device; anonymous usage milestones may be uploaded as described below.

Website analytics

The Matheion website (matheion.zlu.me) records anonymous first-party usage so we can understand which open lessons people open and whether store links are useful. A random visitor id is stored in your browser localStorage. Snapshots may include page paths, coarse funnel milestones, approximate time on site, referrer / campaign parameters when present, and approximate region from the hosting edge.

App install analytics

The Matheion app may periodically upload an anonymous usage snapshot to matheion.zlu.me. Snapshots include a random install id, app version, platform, coarse locale/timezone, approximate usage time, and milestone event names (for example course opened, lesson started, lesson practised, paywall shown). They do not include lesson text, quiz answers, or advertising IDs. Network and approximate location metadata may be attached by our hosting provider from the request.

What we do not collect

• No advertising identifiers or third-party ad analytics
• No sale of personal data

Optional sign-in and subscriptions

If you use a build with sign-in or subscriptions enabled, authentication is handled by our auth provider under their privacy policy. Payment is handled by Apple, Google, or our payment processor; we receive purchase or entitlement status, not full payment card details.

Children

Matheion is an educational app suitable for general audiences. We do not knowingly collect personal information from children through our own services.

Changes

We may update this policy from time to time. The "Last updated" date at the top will change when we do.

Contact

Questions about privacy? Email matheion@zlu.me or visit our support page.