Your data,
the short version.

Your device keeps your learning records so you can study offline. Flua also sends us a detailed study history, even without signing in. On Android and the web, this collection is part of using Flua, and by using Flua you agree to it; Settings → Privacy says the same. On iPhone and iPad it is on by default, and you can turn it off at any time with the Share usage data switch in Settings → Privacy. Turning it off stops Flua collecting new usage data; anything recorded before you switched it off may still finish uploading. To ask about it or object to it, email support@tryflua.com. What we collect:

• Your study progress — which cards you have seen and how the scheduler has timed them.
• Your streak, daily pace and stats.
• Your name, if you entered one during onboarding.

Deleting the app removes its local records. It does not remove records already uploaded to Flua; contact us below to request deletion.

• Website visits. Our web pages tell PostHog about each visit: the page, the link that brought you here, how far you scrolled, which install buttons you tapped, and an approximate location PostHog works out from your connection. We use no cookies and store nothing on your device. Each page view gets a fresh random ID there, so PostHog never joins visits up or ties them to you. To count how many different people visit each day, our own server also keeps a scrambled code made from your IP address, your browser name and the date, with the install buttons you tapped that day and the link tag you arrived with. The code changes every day, so it cannot follow you from one day to the next, and we never keep the address itself.
• Language requests. When you add or vote for a request on the request page, we store the request and a scrambled code made from your IP address and browser name, so each person gets one vote per request. We keep the code, never the address itself.
• Language delivery. To download a language and its audio, your device requests them from our servers. This needs no account and no personal information.
• App check-in. Each time Flua opens or you switch back to it, it tells our servers which version of the app it is running, whether it is on Android, iPhone or the web, and whether it just started or came back. It also sends your device's time zone setting and your approximate connection country, worked out the same way as for study history. We record each check-in under your Flua account, signed in or not. We use this to count how many people use Flua each day and how often they come back, and to keep every device on the current version. It carries no study content and no name. On iPhone and iPad with usage data turned off, the check-in still goes out but carries no time zone or country.
• Reminders. When Flua schedules or cancels a reminder, we record when it is set to appear, its wording, which language it is for, and whether you picked that time or Flua learned it from when you study. When you tap a reminder, we record the tap and when it happened. We also note whether your device allows Flua's notifications. We store this for every learner, signed in or not, so we can tell which reminders actually help. On iPhone and iPad, turning usage data off stops these records.
• If you create an account. We store your email address and your learning progress so we can back it up, sync it to a new device, and restore a purchase you have made.
• Study history. We also store when you first enter onboarding, the display name you enter, your approximate connection country and your device's time zone setting, including when you use Flua without signing in. Country is estimated by Cloudflare from your connection or, when that is unavailable, from your device's time zone; this feature does not store your IP address or precise location. We store session starts, active study time, pauses and endings; the cards shown in order; each Again/Good rating, undo and timestamp; and the card content, scheduling state, settings and app version at that moment. This includes anonymous learners. Offline records upload when your device reconnects. We use them to investigate bugs and measure learning pace. On iPhone and iPad, turning usage data off keeps new detailed history on your device; anything recorded before you switched it off may still finish uploading. Signing in separately enables progress backup and restoration.
• Analytics and diagnostics. Flua sends product-usage, device, performance and crash data to PostHog and Sentry so we can find bugs and improve the app. On iPhone and iPad you can switch this off at any time in Settings → Privacy → Share usage data. Learning and paid access work the same for everyone. We do not use this data for advertising or cross-app tracking.
• Public transparency totals. We may publish cohort-wide totals such as learner count, study hours, cards reviewed and aggregate Again rate. We never publish names, emails, user IDs or individual study histories.

Purchases are securely processed by Apple, Google Play, or Polar. We receive only the purchase and entitlement status needed to unlock access. We do not receive or store your payment card details.

Local data is yours to clear at any time by deleting the app. On iPhone and iPad, you can stop Flua collecting new usage data in Settings → Privacy; anything recorded before that may still finish uploading. If you created an account, open Settings → Account → Delete account in Flua to remove the account and block access immediately. Stored study history is then erased in background batches. If you cannot access the app, use our account-deletion page for the email fallback. Diagnostic records already sent are retained only as long as needed to operate and improve Flua.

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

Service providers. Convex hosts account and synced learning data; RevenueCat reconciles App Store and Google Play entitlements; PostHog and Sentry receive analytics and diagnostics unless you switch them off on iPhone or iPad. Apple, Google Play, or Polar process purchases. These providers process data only to run Flua under their own security and privacy terms.

Changes. If this policy changes, we will update the date above and, for material changes, let you know in the app.