Legal

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 & Sub-Processors

We do not sell, rent, or trade your personal data. We share data only with the following sub-processors, each of which is contractually bound to GDPR-compliant data processing terms:

• Supabase (EU region) — Database and authentication. Stores your account, learning progress, custom cards, language preferences, push notification tokens, and subscription state.
• Vercel — Web application hosting and CDN. Processes request logs and IP addresses for routing, security, and abuse prevention.
• Apple Inc. — Required for the iOS app: (a) Sign in with Apple (you receive an opaque user identifier and, if you opt in, your email); (b) App Store in-app purchases for Lingden Pro; (c) Apple Push Notification service (APNs) for daily reminders, if you enable them.
• Google — Only if you sign in with Google OAuth. We receive your name and email; Google receives confirmation of the authentication event.
• RevenueCat — Manages App Store and Stripe subscription receipts, entitlements, and renewal state. Receives your user identifier and subscription transaction data; does not receive learning content.
• Stripe — Processes payments for web subscriptions. Stripe receives payment information directly; we never see or store your card details.
• OpenAI — Generates flashcard content on demand from your learning prompts (e.g. a target word). The text of your generation requests is sent to OpenAI's API. Your account identifier is not transmitted.
• Google Cloud Text-to-Speech — Synthesizes audio for flashcard pronunciation. Receives the text to be spoken; no account information.
• Cloudflare R2 — Stores generated audio files. Audio files are not linked to your identity at the storage layer.
• Sentry — Error monitoring. May receive a hashed user identifier, error stack traces, device model, OS version, and IP address (for region grouping) when an error occurs. We have configured Sentry to scrub request headers and bodies that may contain personal data.

We do not use any third-party advertising networks, social media trackers, behavioral profiling services, or analytics services that share data with third parties for marketing purposes. We do not use Apple's Advertising Identifier (IDFA) and the iOS app does not request App Tracking Transparency permission.

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@arenorg.com. 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.

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 language-learning platform that uses spaced-repetition flashcards with real sentences, word-by-word breakdowns, IPA pronunciation guides, and contextual learning. The Service is offered through (a) the Lingden web application accessible at lingden.app via modern web browsers and (b) the Lingden iOS application available on the Apple App Store. Lingden offers both free features and optional paid subscriptions, as described in Section 6.

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. Subscriptions, Pricing & Auto-Renewal

6.1 Free and Paid Tiers

Lingden offers a free tier with limited functionality and a paid "Lingden Pro" tier with expanded features. The full set of features available at each tier is presented inside the Service before purchase. The free tier remains available without payment.

6.2 Subscription Plans

Lingden Pro is offered as an auto-renewable subscription with the following options on the Apple App Store:

• Lingden Pro Monthly — 1-month auto-renewing subscription.
• Lingden Pro Yearly — 1-year auto-renewing subscription.

The current price of each plan is displayed inside the Service on the subscription purchase screen and in your local App Store listing prior to purchase. Prices may differ by country and are subject to applicable taxes.

6.3 Billing & Auto-Renewal (Apple App Store)

When you purchase a Lingden Pro subscription through the iOS app:

• Payment will be charged to your Apple ID account at the confirmation of purchase.
• Your subscription automatically renews at the end of each billing period unless auto-renewal is turned off at least 24 hours before the end of the current period.
• Your account will be charged for renewal within 24 hours prior to the end of the current period at the price of the selected plan.
• You can manage your subscription and turn off auto-renewal by going to your Apple ID Account Settings on your device after purchase.
• No cancellation of the current subscription is allowed during an active subscription period; cancellation prevents future renewal but does not refund the current period.
• Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription, where applicable.

6.4 Refunds

Refund requests for purchases made through the Apple App Store are handled by Apple in accordance with Apple's refund policy. To request a refund, visit reportaproblem.apple.com. Aren Organization is unable to process refunds for App Store transactions directly.

6.5 Price Changes

We may change subscription prices from time to time. Any price change will take effect at the start of the next billing period following notice. You will be notified of price changes in accordance with App Store rules and applicable law, and you may cancel your subscription before the new price takes effect.

6.6 Future Plan Changes

We reserve the right to introduce new subscription tiers, modify features included in existing tiers, or change pricing in the future. Material changes will be communicated with reasonable notice. Features available to active Lingden Pro subscribers at the time of purchase will remain available for the remainder of the paid 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.

1. What Are Cookies?

Cookies are small text files stored on your device when you visit a website. They help the website remember your preferences and improve your experience. Similar technologies include localStorage and sessionStorage, which serve comparable purposes.

2. Cookies We Use

Lingden uses only strictly necessary cookies. We do not use any advertising, marketing, or third-party tracking cookies.

3. Why No Cookie Banner?

Under EU GDPR and the ePrivacy Directive, strictly necessary cookies do not require user consent. Since Lingden only uses essential cookies required for the Service to function (authentication and user preferences), we are not required to show a cookie consent banner.

4. Managing Cookies

You can delete cookies and localStorage data at any time through your browser settings. Clearing authentication cookies will log you out, and clearing localStorage will reset your locally cached preferences (your progress is preserved in your account if you are logged in).

5. Third-Party Cookies

Lingden does not set any third-party cookies. If you sign in with Google OAuth, Google may set its own cookies during the authentication flow on Google's domain, governed by Google's Privacy Policy.

Responsible Party

Contact

Data Protection

For data protection inquiries: contact@arenorg.com

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.