プライバシーポリシー
発効日： July 30, 2026
This Privacy Policy explains how your information is collected, used, shared, and protected when you use the Lingaira mobile app and website (together, the "Service"). Lingaira is a language-learning service built around spoken conversation practice with an AI tutor. Please read it together with our Terms of Service.
We aim for this policy to be clear and complete. It is not a substitute for legal advice; if a mandatory data-protection right applies where you live, that right prevails over anything narrower stated here.
1. Who we are (data controller)
The Service is operated by Thieu Tran, an individual developer based in Hanoi, Vietnam("we", "us", "our"). For any privacy question or to exercise your rights, contact us at [email protected]. We are the party responsible for deciding how and why your personal data is processed for the Service.
2. Data we collect
We collect the categories below. We only collect what we need to run the Service, and some items are optional and depend on features you choose to use.
| Category | Examples | Source |
|---|---|---|
| Account & profile | Email, display name, password (stored only as a salted hash), date of birth (used to confirm eligibility), chosen proficiency level, and an optional profile photo. | You |
| Sign-in identifiers | If you sign in with Google or Apple, the identifier and basic profile data those providers return. | Google / Apple |
| Voice & transcripts | The audio you speak during a practice session and the text transcripts derived from it. | You (microphone) |
| Learning data | Pronunciation, grammar, vocabulary and fluency scores, XP, streaks, quest and lesson progress, feedback, and tutor memory (points the tutor remembers to personalise sessions). | Generated from your use |
| Community content | Forum posts and replies, and messages you send in group speaking sessions, plus reports you submit. | You |
| Purchases | Subscription tier, entitlement and transaction status. We do not receive or store your full card details — payment is handled by the app store. | App store / RevenueCat |
| Support data | Support tickets you submit, any screenshots you attach, and basic device diagnostics included with a report. | You |
| Technical & diagnostic | Device and app version, language/timezone, push notification token, IP address, request and security logs, and crash / error diagnostics. | Collected automatically |
3. How we use your data and our legal grounds
We use your data for the following purposes:
- To provide the Service — run real-time conversation practice, transcribe and score your speech, generate feedback, save your progress, and operate community features you choose to use (needed to perform our agreement with you).
- Voice / AI processing — send session audio and transcripts to our AI provider so the tutor can respond and score you. Because this is sensitive, we ask for your explicit consent before your first speaking session, and you can withdraw it (see section 10).
- To keep the Service safe — authenticate you, prevent abuse and fraud, and moderate community content (our legitimate interest in a safe service, and to meet legal obligations).
- To handle payments — manage subscriptions, entitlements and receipts.
- To communicate — send service messages and respond to support requests and rights requests.
- To comply with law — keep records we are legally required to keep and respond to lawful requests.
Where the law requires your consent, we ask for it and you may withdraw it at any time; withdrawing does not affect processing done before you withdrew.
4. Third-party AI and voice processing (Google Gemini)
Our conversational AI, speech transcription and feedback scoring are powered by Google Gemini, provided by Google. To deliver these features, your session audio and the transcripts derived from it are sent to Google's Gemini API for processing in real time. Google processes this data as our service provider to return the AI response and scoring.
Before your first speaking session we ask for your explicit consent to this third-party AI processing. You can decline, but speaking practice cannot work without it. AI responses are generated automatically and may be inaccurate — they are practice aids, not professional advice.
5. Service providers we share data with
We do not sell your personal data. We share it only with providers that help us run the Service, and only as needed for the purpose shown. Each acts under contract and its own terms.
| Provider | Purpose | Data involved |
|---|---|---|
| Google (Gemini API) | Conversation AI, transcription, scoring | Session audio and transcripts |
| Google (Firebase Cloud Messaging) | Push notifications | Push token, notification events |
| Google / Apple sign-in | Social login | Account identifier, basic profile |
| RevenueCat & the app stores | Subscription and purchase management | Purchase and entitlement metadata |
| Sentry | Crash and error diagnostics | Diagnostic, device and log data |
| Cloud hosting & storage (incl. Cloudflare) | Run our servers, deliver media, store uploads | Most Service data in transit / at rest |
We may also disclose data where required by law, to protect the rights and safety of users, or in connection with a business transfer. We keep this list current; if we add a provider that materially changes how your data is handled, we will update this policy.
6. Advertising
The Service does not currently show ads and does not process advertising identifiers for ad targeting. If we enable ads in future, we will update this policy and, where required, ask for your consent and provide ad and tracking choices before any ad data is processed.
7. Data retention
We keep data only as long as needed for the purpose it was collected:
- Session transcripts and chat content are hidden (soft-deleted) after 180 days and permanently removed roughly 30 days after that.
- Account and progress data are kept while your account is active.
- When you delete your account, your personal data is anonymised immediately and permanently purged after a 30-day grace period (this lets you recover from an accidental deletion).
- Backups and legal records (for example, security logs or transaction records we must retain) may persist for a limited additional period and roll off on their own schedule.
Deleting your account does not by itself cancel a subscription bought through an app store — see the Terms of Service and manage or cancel it in your store account.
8. International data transfers
We operate globally and some providers listed above process data outside your country, including outside Vietnam. Where data is transferred across borders, we rely on the provider's contractual data-protection commitments and applicable safeguards. You can ask us for more information about a specific transfer using the contact details below.
9. Your rights and choices
Subject to the law that applies to you, you can ask to access, correct, delete or export your data, object to or restrict certain processing, and withdraw consent. In particular:
- Delete your account and personal data — in the app, Profile → Delete Account, or via our web deletion request.
- Export a copy of your data — in the app, Profile → Download my data (returns your profile, sessions, transcripts, community content and progress as a JSON file).
- Withdraw AI consent or update your preferences from your profile settings.
- Other requests (access, correction, objection, complaint) — email [email protected]. We may need to verify your identity, and we aim to respond within the period required by applicable law.
10. Age requirement (18+)
The Service is intended only for users who are at least 18 years old. We ask for your date of birth at sign-up and block accounts for anyone under 18. We do not knowingly collect personal data from anyone under 18; if we learn that we have, we delete it. Where local law sets a higher minimum age, that requirement applies, and we may limit or decline service until it is met.
11. Security and data breaches
We use technical and organisational measures such as encryption in transit, hashed passwords, access controls and logging to protect your data. No method is perfectly secure, but if a breach affecting your personal data occurs, we will act promptly and notify you and any authority where the law requires it.
12. Voice data and biometrics
We use your voice and transcripts only to provide conversation practice, transcription and feedback. We do not use your voice to create a biometric template or to identify you biometrically.
13. Changes to this policy
We may update this policy as the Service evolves. We will change the effective date above and, for material changes, surface a notice in the app or on our website. If a change requires your consent, we will ask for it before it takes effect.
14. Contact
Questions about this policy or your data? Contact us at [email protected].