1. Categories of personal data
Depending on how you use the app, we may process:
• Account and profile: email address, display name, password (stored only in hashed form on our servers), optional profile photo (“avatar”), subscription or plan status, notification preferences, email verification status where enabled, and registration-related preferences you submit (such as locale).
• Learning activity: quiz attempts, scores, detailed results, and history; progress and interactions with learning modules (including listening content and optional media uploads where the feature allows); text and files you submit for writing exercises; metadata about reading materials you open (for example document identifiers) and related progress where recorded.
• Authentication and device signals: a bearer session token issued by our API is stored on your device using secure storage; if you enable optional quick sign-in, your email and password may also be stored locally in encrypted device storage; a random per-install identifier is created on the device to associate push tokens with your installation; when you sign in or refresh your profile, the app may send your client platform type (such as iOS, Android, or web) to the server.
• Security-related server logs: after successful password login, our backend may record timestamp, platform, IP address (when available), browser/app user agent (truncated), and approximate country derived from IP using a GeoIP database where configured.
• Push notifications: if you grant permission, a Firebase Cloud Messaging (FCM) device token, platform label, and optional device install id may be sent to our servers so we can route notifications to your device.
• Support: when you use in-app support, we process ticket subjects, descriptions, and message content needed to respond.
• Tutoring (where enabled): tutor profiles you view; booking and payment references for tutoring purchases; private learner–tutor chat text; voice recordings you send in chat; and learning materials a tutor shares with you (for example PDF or image files). Chat is limited to authorized participants after a confirmed paid booking (or an authorized administrative assignment). Safety reports you submit (reason, optional details, and minimal message evidence) are processed by authorized moderation staff; we do not reveal your identity as reporter to the reported user.
• Invites / referrals (where enabled): your personal invite or referral code; invite links or codes you open, enter, or follow when registering; and records attributing a new registration to the inviting user for program integrity and abuse prevention.
• Payments: if you purchase a paid plan or a tutoring booking, our servers process payment references, status, amounts, timestamps, and related metadata returned by our payment integration; checkout may continue in an external browser or system web view depending on configuration. Digital subscription unlocks may also use the platform store billing where that product is offered.
• Embedded media: some screens load YouTube videos; when you play them, Google may collect data under its own policies.
2. Purposes and legal bases
We process personal data to:
• Provide and maintain your account (registration, login, logout, password reset, email verification where used).
• Deliver core learning features (quizzes, listening, writing, reading), track progress, and show history and analytics tied to your account.
• Operate notifications you opt into (including reminders or announcements as configured).
• Handle billing, plan upgrades, tutoring bookings, receipts, and customer support.
• Operate private tutoring chat and related safety tools (including report and block) where those features are enabled.
• Operate invite and referral features where enabled (including storing invite codes and attributing registrations to an inviting user).
• Secure the Services (fraud prevention, abuse detection, troubleshooting, audit logs visible only to authorized administrators with elevated roles).
• Meet legal obligations (for example tax or accounting retention for payments).
Depending on your jurisdiction, processing is based on performance of a contract, legitimate interests that are not overridden by your rights (such as service security and product improvement compatible with privacy expectations), consent where required (for example push permission or optional convenience features you turn on), or legal obligation.
3. Servers, API traffic, and logs
The app communicates with our PHP JSON API over HTTPS. Most requests include a locale query parameter so the server can return translated learning content; this is primarily a content-language setting and may differ from the language you chose for the app interface.
Server administrators with appropriate roles may access operational logs (for example API success or error metrics, audit trails, session-resume logs for privileged accounts, and login logs as described above) to keep the platform reliable and secure. Ordinary learner accounts are not used to build unrelated advertising profiles in this app.
4. Local storage on your device
On-device storage includes:
• Session token in secure storage (for example Flutter Secure Storage with encrypted preferences on Android where supported).
• Optional quick sign-in: email and password in secure storage plus a non-secret flag in app preferences indicating the feature is enabled—only if you explicitly opt in.
• A random device install identifier in secure storage, used to correlate push tokens with an installation.
• Theme and locale preferences via standard app storage.
• A pending invite or referral code may be stored temporarily on the device (for example after opening an invite link) until you complete registration or clear it.
Biometric or device-PIN prompts used to unlock quick sign-in or to resume sessions for certain privileged roles are handled by the operating system; we do not receive your raw biometric template.
5. Learning modules, uploads, and media
When you use quizzes, listening exercises, writing prompts, or reading documents, related answers, files, timestamps, and scores may be transmitted to our servers and stored with your user id. Administrators you authorize (for institutional deployments) may review submissions for teaching or moderation. Profile images you upload are processed to normalize format/size before storage. Video or audio you attach where permitted is transmitted over TLS to our API.
Tutor chat voice messages and shared tutoring materials are stored on our servers and are accessible only to authorized conversation participants (and to moderation staff when a report requires review). Microphone access is requested only when you record a voice message.
6. Push notifications (Firebase)
We use Google Firebase with Firebase Cloud Messaging (FCM). When the app starts, Firebase may initialize using platform-specific configuration bundled with the app. If you allow notifications, the OS may show a permission dialog; FCM tokens can change over time and may be refreshed. Tokens are sent to our backend (together with platform and optional install id) so we can target notifications to your device. Foreground messages may be displayed using on-device local notifications. Tutor-chat notifications are designed to avoid placing full private message text on the lock screen (they typically show a generic new-message notice, or a short label such as voice/material). For details on how Google processes data as a processor/infrastructure provider, see Google’s Firebase documentation and privacy policy. You can withdraw push consent in system settings and, where available, in app settings.
7. Embedded YouTube content
Some learning and writing screens embed YouTube players using the official YouTube IFrame API via a Flutter player package. When a video loads or plays, YouTube (Google) may set or read cookies or similar technologies and collect usage and device information according to YouTube’s terms. We do not control YouTube’s data practices; avoid playing embedded videos if you do not wish YouTube to process data.
8. Plans, payments, and receipts
Paid plans and tutoring bookings are prepared through our server-side payment APIs. After you choose to pay, the app opens or redirects you to your payment institution’s secure website (for example your bank’s or the card acquirer’s hosted checkout) in an external browser or system web view—you complete payment on that protected page. Card numbers, card security codes (CVV/CVC), and other payment credentials are entered only there and are processed solely by the bank or licensed payment processor; we do not collect, receive, or store your full card details or those sensitive credentials on our servers or in the app. We only retain non-sensitive data returned by the payment system (such as payment reference, status, amount, and timestamps) so we can activate your plan or tutoring access and meet accounting rules. Where digital purchases are made through the Apple App Store, they use Apple’s billing system under the App Store terms. PDF receipts or receipt emails (where enabled) are generated from billing profile fields configured by administrators, not from your card data. Blocking a chat counterpart does not automatically cancel or refund a paid tutoring booking; contact Support for booking issues.
9. Recipients, processors, and international transfers
We do not sell your personal information to anyone, including for advertising or marketing lists, and we do not rent your data to third parties for those purposes. We share information only with service providers and infrastructure needed to run the Services, including hosting providers, email delivery for verification or password reset, payment processors (who operate the secure checkout where card data is collected), Google (Firebase / FCM, YouTube), GeoIP database vendors used on servers, and software libraries that render PDFs or documents from URLs we provide. Some providers may process data in countries outside your own, including outside the European Economic Area where applicable; we implement appropriate safeguards where required by law (such as standard contractual clauses or equivalent mechanisms).
10. Retention
We keep account and learning data while your account is active and as needed to deliver the Services. Tutor chat messages, voice files, shared materials metadata, and safety reports are retained while needed to provide tutoring and moderation, then deleted or anonymized with your account or under our retention schedules, except where law, safety investigations, or accounting rules require longer retention of booking and payment records. If you delete your account or request erasure where supported, we delete or irreversibly anonymize personal data except where a longer retention period is required for legal claims, security, or statutory accounting and tax obligations. Technical and security logs may be kept for limited periods consistent with operational necessity. Push tokens are removed or replaced when you log out, disable notifications, or uninstall the app (subject to residual server-side cleanup schedules).
11. Security
We use TLS for client–server traffic where configured correctly, role-based access for administrative functions, and secure storage APIs on mobile for sensitive secrets. No method of transmission or storage is completely secure; you are responsible for maintaining the confidentiality of your password and for securing your device with a lock screen.
12. Your rights and choices
Where applicable law grants you rights (including in the EEA, UK, or Switzerland), you may request access, correction, deletion, restriction, objection to certain processing, or portability of your personal data. You can adjust some settings (notifications, quick sign-in) in the app; for account deletion or broader requests, use available in-app tools or contact us via Support or the publisher contact shown in About. You may lodge a complaint with your local supervisory authority.
13. Children
The Services are intended for learners who meet the minimum digital-consent age in their jurisdiction or who use the app with consent and supervision of a parent or guardian. If you believe a child provided personal data without appropriate consent, contact us using the channels in the app and we will take appropriate steps.
14. Changes
We may update this Privacy Policy when features, vendors, or legal requirements change. Material changes will be reflected in the in-app text with a reasonable indication of the update date where practicable. Continued use after the update is posted constitutes acceptance unless applicable law requires a different consent mechanism.
15. Contact
For privacy questions, contact the operator via the About screen in the app (including the publisher website link if shown) or open a Support ticket. We will respond in line with applicable law.
AI-assisted writing reviews
Where enabled, authorized Superadmin reviewers may request an AI draft evaluation of a writing submission. The request is made only from our backend servers to OpenAI (never from the mobile app). We send the examination prompt text, the learner answer text, and the assigned CEFR level. We do not send email addresses, phone numbers, payment information, or other account identifiers to OpenAI for this purpose. AI output is a suggestion only; a Superadmin must review and approve before any score or feedback is published to the learner. The feature can be disabled server-side.
Speak with AI (DEXI) and realtime voice practice
Where Speak with AI is enabled, we process: selected topic and plan/level eligibility; session identifiers; microphone audio you provide during a session; transcripts and AI replies; allowed/remaining speaking seconds; usage ledgers for monthly plan minutes and purchased minute lots; and technical diagnostics needed to run or end a session. During a session, your microphone audio is streamed directly from the app to our AI provider OpenAI (Realtime API), using a short-lived session key issued by our server, solely to provide the real-time DEXI conversation and pronunciation feedback. Deutsch Lernen does not store DEXI voice recordings in its own database or on its own servers. Only the text transcript of the session, AI replies and lesson results are kept. We do not send your email, phone, password, or payment card data to OpenAI for Speak with AI. You can end a session at any time; remaining minutes follow plan and purchase rules. Practice and promotional push reminders about Speak with AI may be sent if notifications are enabled and you have not turned those reminder preferences off in Settings.
Speaking-minute purchases and tutoring payments
If you buy Speak with AI minute packages (including Apple App Store products or complimentary grants issued by Superadmin), we store purchase references, package size, remaining seconds, store/transaction identifiers needed for entitlement and abuse prevention, and related timestamps—not your full card number. Tutoring bookings and learner–tutor chat remain as described above. OpenAI may also be used for AI-assisted writing review drafts (prompt, answer, CEFR only) when Superadmin enables that feature.