Privacy Policy for lingonook

Last updated: June 23, 2026

1. Introduction

This Privacy Policy explains how Manyfold Labs GmbH ("Manyfold Labs", "we", "us", or "our") processes personal data when you use Lingonook at https://lingonook.com.

2. Controller and Contact

The controller responsible for Lingonook is Manyfold Labs GmbH, Waldweg 16, 23795 Bad Segeberg, Germany. You can contact us at manyfoldlabs@gmail.com.

3. Data We Process

Depending on how you use Lingonook, we may process:

Account data such as your name, username, email address, password hash, OAuth provider IDs, profile image, and session information.
Learning data such as selected language, story and chapter progress, vocabulary, flashcards, likes, quiz activity, lesson activity, and feedback you submit.
Purchase and access data such as product plan, payment provider, customer ID, subscription or order status, and entitlement status. Payment card details are handled by payment providers and are not stored by us.
Communication data such as support messages, email signups, lesson PDF download requests, and transactional email delivery information.
Technical data such as IP address, browser and device information, logs, cookies, consent choices, and analytics events.

4. Why We Process Data

We process personal data to provide and secure Lingonook, create and manage accounts, deliver lessons and PDFs, remember learning progress, process purchases, provide support, prevent misuse, send service emails, improve the product, and comply with legal obligations.

5. Legal Bases

Where the GDPR applies, we rely on the following legal bases: performance of a contract, steps requested before entering a contract, consent, legitimate interests such as service improvement and security, and compliance with legal obligations.

6. Cookies and Analytics

Lingonook uses cookies and similar technologies for essential functions such as authentication, security, consent storage, and lesson PDF access. We may also use privacy-conscious analytics such as Plausible to understand aggregate product usage. If support chat is enabled, Crisp may set cookies or process support conversation data.

7. Service Providers

We use third-party providers to operate Lingonook, including hosting and deployment providers, MongoDB database services, AWS S3/CloudFront for media and downloads, NextAuth and OAuth providers such as Google or Discord for login, Lemon Squeezy or Stripe for payments, Brevo for contact and customer email lists, Mailgun for transactional email, Crisp for support chat, and Plausible for analytics. These providers process data only as needed to provide their services to us.

8. International Transfers

Some providers may process data outside Germany or the European Economic Area. Where required, we rely on appropriate safeguards such as adequacy decisions, standard contractual clauses, or equivalent provider commitments.

9. Retention

We keep personal data only as long as needed for the purposes described above, including account operation, access management, support, legal, tax, accounting, and security requirements. You may request deletion of your account data, subject to data we must keep for legal or legitimate reasons.

10. Your Rights

Where applicable, you may have the right to request access, correction, deletion, restriction, portability, or objection to processing of your personal data. You may also withdraw consent where processing is based on consent. To exercise these rights, contact manyfoldlabs@gmail.com.

You also have the right to lodge a complaint with a competent data protection authority.

11. Children's Privacy

Lingonook is not directed to children under 16. We do not knowingly collect personal data from children under 16. If you believe a child has provided personal data, contact us and we will take appropriate steps.

12. Security

We use reasonable technical and organizational measures to protect personal data. No online service can be guaranteed to be completely secure, but we work to keep Lingonook protected and updated.

13. Changes to This Policy

We may update this Privacy Policy from time to time. The updated version will be posted on this page with a new "Last updated" date. For material changes, we may provide additional notice where appropriate.