Lainguist Privacy Policy | Dogu Yilmaz

Lainguist Privacy Policy

Last Updated: July 30, 2026

Overview

Lainguist is a language learning app that helps you improve your English through reading passages, comprehension quizzes, vocabulary cards and word games. This privacy policy explains what information Lainguist collects, how it is used and what choices you have.

The Short Version

  • Your learning data lives on your device first and is mirrored to your account in the cloud so you can restore it.
  • You can use Lainguist without ever entering an email address. An anonymous account is created for you automatically.
  • We never access your microphone, camera, photos, contacts or location.
  • We do not sell your data. We do not send you marketing emails.
  • You can delete your account and its data from inside the app at any time.

Information We Collect

Account Information

  • Anonymous account: When you first open Lainguist, an anonymous account is created automatically through Firebase Authentication. It has a random identifier and contains no personal details.
  • Email and password (optional): If you choose to secure your account, you can link an email address and password. This lets you sign in on another device and recover your progress. We do not verify, sell or send marketing to this address.

Content You Create

The following data is saved locally on your device and synced to your account in the cloud:

  • Vocabulary words you save, including notes, context sentences and deck assignments
  • Reading passages in your library, including text you paste yourself and passages generated for you
  • Prompts you type when generating a passage (topic, characters, setting, situation)
  • Quiz attempts, answers, scores and completion times
  • Your display name and emoji avatar
  • Learning progress: XP, level, streaks, achievements, daily goals and game statistics

Usage and Diagnostic Data

  • Firebase Analytics collects anonymous usage events (screens viewed, features used) along with device model, operating system version and app version.
  • Firebase Crashlytics collects crash reports and device state at the time of a crash so we can fix bugs.

We do not attach your name or email address to analytics data.

Purchase Information

Subscriptions and credit purchases are processed by Apple’s App Store or Google Play. We never see your payment card details. RevenueCat manages subscription status and credit balances using your account’s random identifier. Purchase history tied to that identifier lets us restore your entitlements across devices.

Advertising Data

Lainguist shows optional rewarded ads through Google AdMob (for example, watching an ad to earn credits). The Google Mobile Ads SDK may access device advertising identifiers. Lainguist requests non-personalized ads. On iOS, Apple’s App Tracking Transparency prompt asks for your permission before any cross-app tracking identifier is used and you can decline it without losing any functionality.

AI-Generated Content

When you generate a reading passage, the prompt details you enter and any text you paste are sent to our server and processed by Google Gemini to create the passage and its quiz questions. This content is processed to provide the feature and is not used by us for any other purpose. Do not paste text containing sensitive personal information.

Dictionary Lookups

When you look up a word, the app queries the free Dictionary API (api.dictionaryapi.dev) directly from your device. That service receives the looked-up word and your IP address, as with any web request. No account information is sent with the request.

Social Features

  • Friends: You can send a friend request by entering another user’s email address. The address is used only to look up the account and is never stored in your friend list, displayed to others or emailed. Only mutual friends can see each other’s profile and progress.
  • Weekly leaderboard: If you participate, your display name, emoji avatar, XP and level are visible to other signed-in users for that week. You control your display name and can use any nickname.
  • Duels: Match results and ratings are shared with your opponent.

Text to Speech

Word and passage pronunciation uses the voices built into your device’s operating system. Your voice is never recorded. Lainguist has no microphone access.

Information We Do NOT Collect

  • Microphone or voice recordings
  • Camera or photo library access
  • Location information
  • Contacts
  • Advertising profiles built by us
  • Payment card details

Where Your Data Is Stored

  • On your device: Your learning data is stored locally first, so the app works offline.
  • In the cloud: Your account data is mirrored to Google Firestore hosted in the European Union (multi-region eur3). All traffic between the app and our servers uses HTTPS.

Third-Party Services

Lainguist relies on the following services, each governed by its own privacy policy:

Data Retention and Deletion

  • Delete your account: Settings → Account → Delete account. This permanently removes your authentication account and the cloud data linked to it and clears the app’s data on your device.
  • Clear local data: Settings → Data lets you clear quiz history, word cards or all local data without deleting your account.
  • Sign out: Signing out removes your synced data from the device.

If you cannot access the app, you can request deletion by email and we will remove your account and associated data.

Your Rights

Depending on where you live (including under GDPR and CCPA), you have the right to:

  • Access the data associated with your account
  • Correct inaccurate data
  • Delete your account and data
  • Object to or restrict processing
  • Withdraw consent (for example, declining the iOS tracking prompt)

To exercise any of these rights, use the in-app controls described above or contact us by email.

Children’s Privacy

Lainguist is not directed at children under 13 and we do not knowingly collect personal information from children. If you believe a child has provided personal information through the app, contact us and we will delete it.

Security

Data in transit is encrypted with HTTPS. Cloud data is protected by per-account access rules, so only you (and mutual friends, for the limited profile data described above) can read your data. No method of storage or transmission is completely secure, but we follow platform best practices to protect your information.

Changes to This Policy

If we change this policy, we will update the “Last Updated” date above. Material changes will be communicated through the app or the store listing.

Contact

If you have questions about this privacy policy or your data:

This privacy policy applies to the Lainguist mobile application published by Dogu Yilmaz and is effective as of the date listed above.