Last updated: August 21, 2026
Rosenstare LLC (“Rosenstare,” “we,” “us,” or “our”) provides a language-learning application called Lingjini that lets you create vocabulary decks, generate example sentences and definitions, and study with spaced-repetition reviews. This Privacy Policy explains how we handle information when you use the Lingjini app and related services.
Information We Collect
Account information. Lingjini uses Sign in with Apple. When you sign in, we receive an Apple authentication credential and create or access your Lingjini account. If you choose to share an email address with Apple, we may receive the email address Apple provides, which may be an Apple private relay address.
Learning content. We collect the content you create or submit in the app, including deck names, selected language, words or phrases, definitions, example sentences, translations, and regenerated-example history.
Study and account activity. We collect information needed to provide your study schedule and sync your library, such as card status, whether you marked a card as remembered or forgotten, review timing, due dates, and account-linked identifiers.
Subscription information. Purchases are processed by Apple through the App Store. We do not receive your full payment-card or banking details. We receive information needed to verify and provide your subscription, such as your subscription product, entitlement status, App Store transaction identifier, storefront country code, and an account-linked subscription token.
Information stored on your device. The app stores a local copy of your learning library, study statistics, app preferences, and pending review information on your device. Authentication and subscription tokens are stored in Apple Keychain where available.
How We Use Information
We use the information described above to:
- authenticate you and maintain your account;
- sync your decks, cards, and review schedule across signed-in sessions;
- generate definitions, example sentences, and translations requested by you;
- provide spaced-repetition scheduling and in-app study statistics;
- verify, administer, and enforce subscription access; and
- protect the security and reliability of our service.
Please do not enter sensitive personal information into vocabulary, definition, or other free-text fields.
How Information Is Shared
We share information only as needed to operate the service:
- Apple. Apple provides Sign in with Apple and processes App Store purchases and subscription transactions under Apple’s own privacy practices.
- Our service providers. We use service providers that operate the Lingjini API, hosting, and requested language-content generation on our behalf. They may process account identifiers, subscription-verification information, and the learning content necessary to provide the requested feature.
- Legal and safety reasons. We may disclose information when reasonably necessary to comply with law, enforce our terms, or protect users, Rosenstare LLC, or others.
We do not sell personal information or use information from Lingjini for cross-context behavioral advertising. We do not use the app to track you across apps or websites owned by other companies.
What We Do Not Collect Through the App
Lingjini does not request access to your precise location, contacts, photos, camera, microphone, or payment-card details. Text-to-speech playback uses your device’s speech-synthesis features; Lingjini does not record your voice.
Data Retention
We retain account, subscription-verification, and synced learning information for as long as needed to provide the service, comply with legal obligations, resolve disputes, and enforce agreements. Local information remains on your device until you delete it, delete the app, or clear the app’s data, subject to your device and backup settings.
Deleting a deck or card in Lingjini sends a deletion request for that item to our service. Signing out ends your active session but does not by itself delete your Lingjini account or synced learning data.
Your Choices and Requests
You may manage your Apple account and private relay email settings through Apple. You may manage or cancel subscriptions through your Apple App Store account settings.
To request access to, correction of, or deletion of your personal information or Lingjini account, contact us. We may need to verify your identity before fulfilling a request.
Security
We use reasonable safeguards designed to protect information, including encrypted HTTPS connections for communications with the Lingjini API and Apple Keychain storage for certain credentials. No method of transmission or storage is completely secure.
Children’s Privacy
Lingjini is not directed to children under 13. We do not knowingly collect personal information from children under that age. If you believe a child has provided personal information to us, contact us.
International Users
Your information may be processed in countries where Rosenstare LLC or its service providers operate. Those countries may have data-protection laws different from those in your country of residence.
Changes to This Policy
We may update this Privacy Policy from time to time. We will post the updated version here and revise the “Last updated” date.
