Legal
Last updated: March 27, 2026
I. Privacy Policy
1. Who We Are
Lingden ("we", "us", "our") is a language-learning platform operated by Aren Organization. This privacy policy explains how we collect, use, store, and protect your personal data when you use our website, web application, and related services (collectively, the "Service").
2. Data We Collect
2.1 Account Information
When you create an account, we collect your email address and, if you sign in with Google, your name and profile picture as provided by Google. We use Supabase Authentication to securely manage your credentials.
2.2 Learning Progress
We store your flashcard review history, spaced-repetition progress (box level, review counts, next review dates), selected language, CEFR level preferences, and daily card limits. This data is necessary to provide the core functionality of the Service — personalized spaced-repetition learning.
2.3 Gamification Data
We track XP points, streaks, achievements, and session statistics to provide motivational features. This data is stored locally in your browser and, for logged-in users, synced to our database.
2.4 Usage Analytics
We collect anonymous page view data (page visited, timestamp, referrer, country derived from IP) to understand how our service is used. We do not use third-party analytics trackers. IP addresses are not stored — only the derived country code is retained.
2.5 Local Storage
We use your browser's localStorage to cache learning preferences and progress for faster loading. This data stays on your device and is not transmitted unless you have an account, in which case it is synced to our servers.
3. How We Use Your Data
- To provide and personalize the language-learning experience
- To sync your learning progress across devices
- To calculate spaced-repetition schedules for optimal learning
- To track streaks, XP, and achievements for motivation
- To improve the Service based on aggregate, anonymous usage patterns
- To communicate important service updates (only if you opt in)
4. Legal Basis for Processing (GDPR)
We process your personal data under the following legal bases:
- Contract performance — Processing your account and learning data is necessary to provide the Service you signed up for (Article 6(1)(b) GDPR).
- Legitimate interest — Anonymous analytics help us improve the Service without impacting your privacy (Article 6(1)(f) GDPR).
- Consent — For any optional data processing (e.g., marketing emails), we will ask for your explicit consent (Article 6(1)(a) GDPR).
5. Data Storage & Security
Your data is stored securely on Supabase infrastructure hosted within the European Union. We use industry-standard encryption (TLS/SSL) for data in transit and encryption at rest for stored data. Access to production databases is restricted to authorized personnel only. We implement Row Level Security (RLS) policies ensuring users can only access their own data.
6. Data Sharing
We do not sell, rent, or trade your personal data. We share data only with:
- Supabase — Our database and authentication provider (data processor, GDPR-compliant).
- Vercel — Our hosting provider for the web application (data processor, GDPR-compliant).
- Google — Only if you choose to sign in with Google OAuth. We receive your name and email; Google receives confirmation of the authentication event.
We do not use any third-party advertising networks, social media trackers, or analytics services that would share your data with third parties.
7. Your Rights (GDPR)
Under the General Data Protection Regulation, you have the right to:
- Access — Request a copy of all personal data we hold about you.
- Rectification — Correct any inaccurate personal data.
- Erasure — Request deletion of your account and all associated data ("right to be forgotten").
- Data portability — Receive your data in a structured, machine-readable format.
- Restriction — Request that we limit processing of your data.
- Objection — Object to processing based on legitimate interest.
- Withdraw consent — Where processing is based on consent, you may withdraw it at any time.
To exercise any of these rights, please contact us at contact@lingden.app. We will respond within 30 days as required by GDPR.
8. Data Retention
We retain your personal data for as long as your account is active. If you delete your account, all personal data (profile, learning progress, custom cards, gamification state) is permanently deleted within 30 days. Anonymous, aggregated analytics data may be retained indefinitely as it cannot be linked back to you.
9. Children's Privacy
Lingden is not directed at children under 16. We do not knowingly collect personal data from children under 16. If you believe a child under 16 has provided us with personal data, please contact us and we will delete it promptly.
10. International Transfers
Your data is primarily processed and stored within the EU/EEA. If data is transferred outside the EEA (e.g., for CDN delivery via Vercel), we ensure appropriate safeguards are in place, including Standard Contractual Clauses (SCCs) as approved by the European Commission.
11. Changes to This Policy
We may update this privacy policy from time to time. We will notify registered users of material changes via email. The "Last updated" date at the top reflects the most recent revision.
II. Terms of Service
1. Acceptance of Terms
By accessing or using Lingden ("the Service"), operated by Aren Organization ("we", "us", "our"), you agree to be bound by these Terms of Service. If you do not agree to these terms, please do not use the Service.
2. Description of Service
Lingden is a free language-learning platform that uses spaced-repetition flashcards with real sentences, word-by-word breakdowns, IPA pronunciation guides, and contextual learning. The Service is provided as a web application accessible through modern web browsers.
3. User Accounts
- You may use basic features without an account. Creating an account enables progress syncing across devices.
- You must provide accurate information when creating an account.
- You are responsible for maintaining the security of your account credentials.
- You must be at least 16 years old to create an account.
- One person may not maintain more than one account.
- You must notify us immediately of any unauthorized use of your account.
4. Acceptable Use
You agree not to:
- Use the Service for any unlawful purpose or in violation of any applicable laws.
- Attempt to gain unauthorized access to the Service, other accounts, or related systems.
- Interfere with or disrupt the Service, servers, or networks.
- Scrape, crawl, or use automated means to access the Service without our written permission.
- Reverse engineer, decompile, or disassemble any part of the Service.
- Use the Service to transmit malware, spam, or harmful content.
- Impersonate any person or entity, or misrepresent your affiliation.
5. Intellectual Property
5.1 Our Content
The Service, including its design, code, illustrations, flashcard content, algorithms, and branding, is owned by Aren Organization and protected by copyright and other intellectual property laws. You may not copy, modify, distribute, or create derivative works without our written permission.
5.2 User Content
Any custom flashcards or content you create through the Service remain your property. By using the Service, you grant us a limited license to store, process, and display your content solely for the purpose of providing the Service to you.
6. Free Service & Future Changes
Lingden is currently offered free of charge. We reserve the right to introduce premium features, modify the free tier, or change pricing in the future. We will provide reasonable notice of any material changes. Free features available at the time of your registration will remain available to you for a reasonable transition period.
7. Service Availability
We strive to keep the Service available 24/7 but do not guarantee uninterrupted access. The Service may be temporarily unavailable due to maintenance, updates, or circumstances beyond our control. We are not liable for any loss or inconvenience caused by downtime.
8. Disclaimer of Warranties
The Service is provided "as is" and "as available" without warranties of any kind, whether express or implied. We do not guarantee that the Service will be error-free, secure, or meet your specific learning goals. Language-learning outcomes depend on individual effort and consistency.
9. Limitation of Liability
To the maximum extent permitted by applicable law, Aren Organization shall not be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of data, loss of profits, or interruption of service, arising from your use of or inability to use the Service.
10. Account Termination
You may delete your account at any time through the settings page. We may suspend or terminate your account if you violate these terms. Upon termination, your personal data will be deleted in accordance with our Privacy Policy.
11. Changes to These Terms
We may update these terms from time to time. We will notify registered users of material changes via email or an in-app notice. Continued use of the Service after changes take effect constitutes acceptance of the revised terms.
12. Governing Law
These terms shall be governed by and construed in accordance with the laws of Norway, without regard to its conflict of law provisions. Any disputes shall be resolved in the competent courts of Norway.
IV. Imprint
Responsible Party
Aren Organization
Norway
Contact
Email: contact@lingden.app
Website: lingden.app
Data Protection
For data protection inquiries: contact@lingden.app
Dispute Resolution
The European Commission provides an online dispute resolution platform at https://ec.europa.eu/consumers/odr. We are not obligated and generally not willing to participate in dispute resolution proceedings before a consumer arbitration board.
Liability for Content
As a service provider, we are responsible for our own content on these pages in accordance with general laws. However, we are not obligated to monitor transmitted or stored third-party information or to investigate circumstances that indicate illegal activity.
Liability for Links
Our service may contain links to external third-party websites over whose content we have no influence. The respective provider or operator of the linked pages is always responsible for the content of the linked pages.
Copyright
The content and works created by Aren Organization on these pages are subject to copyright law. Duplication, processing, distribution, and any form of commercialization beyond the scope of copyright law require prior written consent. Downloads and copies are only permitted for private, non-commercial use.
Questions?
For any legal, privacy, or general questions, contact us at contact@lingden.app