Privacy Policy
Last updated: 2026-11-11
What we collect
- Your account: you sign in with Apple or Google (through Google Firebase Authentication). We receive a user ID, your name and email (Apple may give us a private relay email instead).
- Your country (from your phone's region setting) — for the country ranking.
- Your quiz activity: answers, time taken, rating, streak, chosen markets and experience level, time zone.
- Subscription status (plan and expiry date) from Apple / Google through our payment provider RevenueCat. We never see your card details.
How we use it
- To run the quiz: pick questions at your level, keep your daily limit, rating, streak and ranking.
- To show the ranking: subscribers' display names, country flag, rating, streak and average answer time are visible to other subscribers.
- To improve questions (for example, which charts most people get wrong).
We do not sell your data and we do not show third-party ads.
Service providers
- Apple and Google — sign-in, app stores and payments.
- Google Firebase — sign-in.
- RevenueCat — subscription management.
- Anthropic (Claude) — writes the chart explanations. Only chart data is sent, never your personal data.
- Our hosting provider — stores the database.
Keeping and deleting data
We keep your data while you use BOS. You can delete your account and all its data at any time in the app (menu ⋮ → Delete account), or email support@example.com and we will do it within 30 days.
Children
BOS is not meant for children under 13.
Changes
If we change this policy we will update the date above and tell you in the app if the change is important.
Contact
support@example.com