Privacy Policy

MathBook — web (riyaziat.com) and the MathBook mobile apps. Last updated 17 July 2026.

MathBook is an interactive mathematics library. This policy explains, plainly, what data the app and website handle. The guiding principle is local‑first: the app works without an account, and your activity stays on your device unless a feature you actively use needs a server.

What we do NOT do

No advertising. No third‑party analytics or tracking SDKs. No selling or sharing of personal data. No account is required to read.

Data stored on your device

Reading progress, bookmarks and notes are stored locally on your device (browser localStorage on the web; app storage on mobile). This never leaves your device unless you sign in to an optional Ferkans account (see below), and you can clear it any time by clearing the app's data.

Media streaming

Figures and videos are not bundled in the app; they are streamed from our server riyaziat.com (hosted in the EU). Requesting them transmits your device's IP address to that server, as with any website. Server access logs (including IP) are kept briefly for security and operations, then rotated.

Optional AI "Plan" feature

If you use the optional planning feature, the topics you type (and any content you provide to it) are sent to an EU academic AI provider (GWDG, Gesellschaft für wissenschaftliche Datenverarbeitung mbH Göttingen) to generate a study plan. If you do not use this feature, nothing is sent. Do not enter personal or sensitive information into it.

Optional Ferkans account

If a version of the app offers sign‑in and you create a Ferkans account, your email address and reading state (progress, bookmarks, notes) are stored by our identity provider Supabase on servers in the EU (Frankfurt), so your data can sync across your devices. This is optional; signed‑out use remains fully local. Voice/audio recordings, if any, are never uploaded.

Legal bases (GDPR)

Art. 6(1)(b) (performance of a contract) for account features you request; Art. 6(1)(f) (legitimate interest) for brief security logs and for serving requested media.

Your rights

You may request access to, correction of, export of, or deletion of any personal data we hold, and you may withdraw consent at any time. To exercise these rights, or for any privacy question, contact us at the address below. You also have the right to lodge a complaint with a data protection authority.

Children

MathBook is intended for a general and educational audience and is not directed to children under 13. We do not knowingly collect personal data from children.

YouTube API Services

Ferkans uses YouTube API Services to publish our own first‑party educational videos to our official YouTube channel. This upload is performed by an internal, server‑side tool and authenticates as the channel owner; it does not access any viewer's or third party's YouTube data or account. By using features that rely on YouTube, you also agree to the YouTube Terms of Service, and Google's handling of data is described in the Google Privacy Policy.

We do not collect, store, or share any personal data of YouTube users through the API. Any data our tool holds about our own uploaded videos (titles, descriptions, video IDs) can be deleted on request, and access/authorization tokens can be revoked at any time via the Google account's security settings. To request deletion of any data we hold, contact us at the address below.

Contact

Amir Rezaei
Dovestr. 5, 10587 Berlin, Germany
ferkans.team@gmail.com