Privacy Policy

Data we collect

You can use QIZU without an account — the app then stores your data under a random anonymous identifier, and we receive no personal information about you. When you sign in with Google we receive your email address, display name and profile picture — used solely to identify your account. In both cases the app stores the quiz sets and cards you create and your practice statistics (cards answered, time practiced, streaks). We do not collect any other personal data.

Purpose of data collection

Your data is used solely to sync your quiz library across your devices and to show you your own learning statistics within the app.

Data storage and security

We store your data securely on Google's Firebase platform (Cloud Firestore, hosted in Zürich, Switzerland), encrypted in transit. Crash reports — device model, operating system, app version and crash traces, never your quiz content — are processed by Firebase Crashlytics to keep the app reliable, grouped under a random crash-reporting installation identifier that is not linked to your account, and can be turned off at any time under Settings → Privacy. Firebase App Check verifies that requests come from the genuine app, using a Play Integrity attestation and a Firebase installation ID (not tied to you or your device hardware). A random per-installation code is stored with the account to make the free word-list import retry-safe, and redeeming a QIZU+ code stores the code and the time of redemption with the account. As with any Firebase-backed app, Google records the IP address and user agent of requests for sign-in security and in function logs.

Two kinds of content are fetched from static web servers rather than Firebase: ready-made word lists from qizu.net (served by GitHub Pages) and, with QIZU+, card audio from audio.qizu.net (served by Cloudflare). Like any web server, they record the IP address and user agent of each request in their logs. A request names only the list or the audio file being fetched — audio files are identified by an opaque code, and your own cards are never sent to either server.

If you report a problem with a card from within the app, the report you choose to send contains that card's text, the answer you typed, the kind of problem and your optional note, and is stored in Firestore with your account so we can fix the content. Reports are deleted together with your account.

Cookies and tracking

QIZU does not use cookies, advertising identifiers, analytics, or any tracking technologies.

Subscriptions

The optional QIZU+ subscription is processed entirely by Google Play. We never see or store your payment details; we only learn whether a subscription is active.

Data sharing

We do not share your personal data with any third parties other than Google as part of the Firebase and Google Play services named above, and GitHub and Cloudflare, whose servers deliver the word lists and card audio described above.

Data retention

Your data is retained for as long as your account exists. You may delete your account and all data at any time. If you use QIZU without signing in, your data is tied to that device's anonymous identifier; Settings → Delete account is available there too and removes the data and the anonymous identifier itself from our servers (Delete all data removes the data but keeps the identifier). Uninstalling the app without doing so leaves the data stored but permanently inaccessible to anyone, including you.

User groups

All user groups are treated equally. We do not apply different rules or collect different data based on age or other characteristics.

Your rights

You can delete your account and all data directly in the app (Settings → Delete account), or follow our Data Deletion Policy. Individual quiz sets can be exported as CSV inside the app; you may also request a copy of your data via the contact below.

Children

QIZU is not directed at children under 13 and we do not knowingly collect data from them.

Changes to this policy

If we change what QIZU collects, we will update this page and change the date at the top.

Contact

For questions or requests, email hi@QIZU.net.