Privacy policy

Brain Quiz app (iOS and Android)

You can use the 3D brain and the quiz library without an account.

• Account (optional): if you sign in with Apple or Google, we keep your email address (Apple may give us a private relay address), your name if the provider shares it, and a user ID, with our sign-in provider Supabase, hosted in the EU. We use them only to sign you in and to count your daily Brain AI answers.
• Brain AI and quizzes from your slides: when you ask Brain AI a question or upload slides, the text of your question, or the text read from your slides, goes through our server to DeepSeek, a third-party AI service, which writes the answer or picks the structures for the quiz. The app asks for your permission before the first time. DeepSeek handles that text under its own privacy policy and may store it on servers in China, so don't include personal or health details. We don't keep your files; the quiz made from them is saved on your device.
• Your quiz results, streak, saved quizzes and per-region statistics are stored on your device. Deleting the app deletes them.
• Usage analytics: the app sends usage events (screens opened, quizzes started and finished, answers given, questions asked), a random install identifier, device model, OS version and app version to PostHog, hosted in the EU. Once you sign in, these events are linked to your user ID. Sessions may be recorded as screen replays to find bugs; text you type is masked. This data is used only to improve the app, is never sold, and is not used to track you across other companies' apps or websites.
• Ads: the app may show a banner from Google AdMob. Ads are non-personalized. In the EU and UK you are asked for consent first. AdMob may collect your device's advertising ID, IP address and ad interaction data under Google's privacy policy.
• Deleting your account: in the app, open Me and tap Delete account. Your account and its sign-in data are deleted straight away.
• The 3D brain model, the questions and the articles are bundled with the app.

Links to external sites (for example the source of the 3D model) open in your browser; their privacy terms apply there.

brainquiz.study

You can sign in on the website with Google or Apple, and Brain AI works there as in the app: the same account data is kept and your questions go to DeepSeek in the same way. The website uses PostHog (EU-hosted) for usage analytics, which stores a random identifier in your browser. The hosting provider receives your IP address in order to deliver the pages; we do not use it to identify you.

Contact

Questions about this policy can be raised at https://github.com/rpaszekdev/brain-quiz/issues.