Langco Privacy Policy

Last updated: July 2026

Langco ("we", "our", or "us") is a language coaching app that helps you learn English through sentence translation and spaced repetition. This policy explains what data we collect, how we use it, and your rights.

1. Data We Collect

Account information — when you sign in with Google or email, we receive your email address and display name. We use this to identify your account and sync your progress across devices.
Study progress — sentences you are learning, review history, streaks, and session results. Stored in your personal account on Firebase Firestore.
Custom sentences — any sentences you add manually to your personal learning list.
App usage data — crash reports and error logs via Firebase Crashlytics to help us fix bugs. These do not include your personal content.
Advertising identifiers — if you are a free user, Google AdMob may collect your advertising identifier and device information to serve personalised ads. Pro users do not see ads.
Purchase information — if you upgrade to Langco Pro, your purchase is processed by Google Play. We record your Pro status locally on your device.

2. How We Use Your Data

To provide and improve the Langco learning experience.
To sync your progress across devices when you are signed in.
To generate AI-powered custom sentences via our secure cloud service (requires sign-in).
To send daily study reminders (only if you enable them in Settings).
To diagnose and fix crashes and technical errors.
To serve advertisements to free users (via Google AdMob).

3. Data Sharing

We do not sell or rent your personal data. Data is processed by the following sub-processors:

Google Firebase (Authentication, Firestore, Crashlytics) — Firebase Privacy Policy
Google AdMob — serves ads to free users and may collect advertising identifiers — Google Privacy Policy
Google Play Billing — processes in-app purchases — Google Privacy Policy
Anthropic — processes your custom sentence text to generate learning content (no text is stored by Anthropic beyond the API call) — Anthropic Privacy Policy

4. Data Retention

Your data is retained as long as your account is active. You can delete your account and all associated data at any time from Settings → Account → Delete account inside the app, or by visiting our account deletion page.

5. Children

Langco is not directed at children under 13. We do not knowingly collect data from children under 13. If you believe a child has provided us with personal information, please contact us so we can delete it.

6. Security

All data is transmitted over HTTPS and stored in Firebase, secured by Google. We do not store passwords — authentication is handled by Google Sign-In or Firebase Email/Password Auth.

7. Your Rights

You may request access to, correction of, or deletion of your personal data at any time by using the in-app account deletion feature or contacting us at the email below. EEA/UK users have additional rights under GDPR including data portability and the right to object to processing.

8. Ad Consent (EEA / UK Users)

If you are in the European Economic Area or United Kingdom, we will ask for your consent before showing personalised ads, in accordance with the IAB TCF framework via Google's User Messaging Platform. You can change your consent choices at any time from Settings.

9. Changes to This Policy

We may update this policy from time to time. Continued use of Langco after changes constitutes acceptance of the updated policy. Material changes will be announced via an in-app notice.

10. Contact

For privacy questions or data requests, contact us at: vincentlivin9@gmail.com