Privacy Policy

1. Information we collect

Account information

We process information used to create and secure your account, such as your email address, display name, account identifier, authentication provider, and sign-in records.

Words and learning activity

We process words, meanings, examples, imported vocabulary, lists, favorites, language choices, learning level, searches, word views, practice sessions, responses, progress, and related timestamps that you save or generate through the Service. Some information is stored locally on your device. If cloud syncing is enabled, eligible data is also transmitted to and stored by our service providers.

Cloud syncing is separate from online features. Account services, dictionary requests, AI features, issue reports, and notification features may send the information needed to operate them to our servers even when your vocabulary collection is not cloud-synced.

Notifications

For notification features, we process an installation identifier, push token when available, time zone, language, notification settings, and relevant learning activity. This can include dictionary word identifiers, learned words and their learning dates, the last practice review time, and remaining practice counts. We use this information to choose daily words and deliver practice and review reminders. Push delivery also involves Expo and the Apple or Google push services; notifications may include vocabulary and practice information visible on your lock screen, depending on your device settings.

Subscription information

Apple or Google processes your payment details. We receive limited purchase information needed to verify and manage access, such as the store, product identifier, purchase token or transaction identifier, subscription status, and expiration date. We do not receive your full payment-card number.

Technical and support information

We and our hosting providers may process device, app version, network, IP address, request, diagnostic, security, and crash information. If you contact us, we receive the information you include in your message and attachments.

When you report a word issue, we store your message and the word’s language, meaning, and example, and send these together with your account email and identifier to our support inbox through Resend. Synchronization diagnostics can include error details and counts of pending learning records. Avoid including sensitive information in reports or support messages.

Device storage and pronunciation

The app uses local storage for sign-in sessions, preferences, and learning records. Pronunciation playback passes the selected text to your device’s speech service. This playback feature does not require you to record or upload your voice to us.

2. How we use information

• provide, personalize, synchronize, and maintain the Service;
• authenticate accounts and protect users and the Service;
• verify subscriptions and provide paid features;
• generate AI explanations, example sentences, and Daily Tips;
• deliver notifications according to your settings;
• respond to requests, investigate word issues, and provide support;
• diagnose problems and improve reliability and usability; and
• comply with law and enforce our agreements.

Legal bases for EEA and UK users

We process information necessary to perform our contract with you, including providing your account, requested learning features, and subscriptions. We rely on our legitimate interests in protecting the Service, preventing abuse, resolving support issues, and improving reliability and educational quality, where those interests are not overridden by your rights. Quality monitoring includes checking the accuracy, relevance, and clarity of Tutor answers and evaluating response times, errors, and operating costs. You may object to processing based on legitimate interests as explained in Section 7. Where consent is required, we rely on your consent, which you may withdraw. We also process information when necessary to comply with legal obligations. If you do not provide information necessary for a feature, we may be unable to provide it.

3. AI features

AI Tutor, generated example sentences, and Daily Tips use OpenAI’s API. When you ask Tutor a question or request examples, we send the request, relevant recent conversation history, and learning context to OpenAI to generate a response. Context can include the selected word, its language, meanings, and example sentences, or the Daily Tip you are discussing and its learning level. Daily Tips are generated using the learning language, selected level, date, and recent generated tips to avoid repetition. Daily Tips can be generated when the app requests a tip, without you sending a chat message, and are shared across users with the same language, level, and day.

We do not add your account email, display name, or account identifier to these AI prompts. However, personal information you put in a question, word, meaning, or example can be included. Requests go through our backend, where they are associated with your account.

We store Tutor questions, answers, generated examples, word or tip context, timestamps, and usage information to restore your current conversation, enforce usage limits, and operate the feature. Starting a new conversation removes the previous conversation from the app’s view; it does not immediately delete it from our systems. To request deletion of your account or Tutor history, contact us at [email protected]. When we delete your account from our application database, its associated Tutor conversations are also deleted; backups and records retained for legal or security purposes are subject to Section 5. We also retain generated Daily Tips so they can be reused for the same language, level, and day.

Authorized personnel may review relevant Tutor content to assess educational quality, investigate reported problems, and detect or investigate misuse, including attempts to bypass AI safeguards. These reviews are distinct from an AI provider using data to train its general-purpose models.

We use Langfuse Cloud to monitor and evaluate Tutor quality, performance, reliability, and safety. We may send Langfuse the questions and recent conversation context included in a Tutor request, the selected word or tip context, generated responses, account and conversation identifiers, timestamps, model information, token usage, estimated costs, and error or request-status information. These records can be linked to your account and are not anonymous. Langfuse processes these records for us as a service provider.

Our AI requests disable OpenAI response storage. This setting does not mean that no data is retained by the provider; OpenAI may process and retain information under its applicable service terms and data policies. We have disabled optional sharing of API data with OpenAI for model improvement. The content we send to OpenAI to provide these features is not used to train OpenAI’s models. Its standard abuse-monitoring logs may contain prompts and responses and are generally retained for up to 30 days, with exceptions for legal obligations and preventing harm. See OpenAI’s API data controls. Do not include sensitive personal information in your questions.

4. How we disclose information

We may disclose information:

• to infrastructure, authentication, database, hosting, email, AI, notification, and support providers that process it for us, including Supabase for authentication, OpenAI for AI generation, Langfuse Cloud for Tutor monitoring and evaluation, Resend for word-issue emails, and Expo for push delivery;
• to Apple and Google for app distribution, purchases, subscription management, and fraud prevention;
• when required by law or to protect rights, safety, and security;
• in connection with a merger, financing, acquisition, reorganization, or sale of all or part of our business; or
• with your direction or consent.

We do not sell personal information and do not use it for targeted advertising or cross-context behavioral advertising.

5. Retention

We retain information for as long as reasonably necessary to provide the Service, maintain business and security records, resolve disputes, and meet legal obligations. Retention periods vary by data type and purpose. We do not apply a single fixed expiration period to all conversations or monitoring records. The criteria below determine how long we keep them.

• Account and saved learning records, including available Tutor history, are retained as needed to maintain your account and provide learning continuity, subject to deletion requests and applicable exceptions.
• Tutor monitoring records, including copies in Langfuse Cloud, are retained while needed to evaluate answer quality and performance, investigate errors or misuse, and assess whether changes improve the Service. We consider the age and sensitivity of the records, whether an issue remains unresolved, and whether aggregate or anonymized information would meet the same need. Keeping saved history does not by itself justify keeping a monitoring copy.
• Support, transaction, security, and dispute records are retained for the relevant support or investigation needs and any applicable accounting, legal, or limitation periods. Specific incident records may need to be retained after other account information is deleted.

We periodically review continued retention and delete or anonymize personal information when it is no longer needed for these purposes. Deletion requests cover associated monitoring copies, subject to the same applicable exceptions. Retention without a preset deadline does not remove your deletion or objection rights.

Information stored only on your device remains there until you remove it, clear app data, or uninstall the app. Backup deletion may take additional time. Restarting a Tutor conversation, deleting a local word, signing out, or uninstalling the app does not itself delete server-side Tutor history or support correspondence.

6. Security

We use reasonable administrative, technical, and physical safeguards designed to protect information. No method of transmission or storage is completely secure, so we cannot guarantee absolute security.

7. Your choices and rights

You can edit certain account and learning information in the Service and manage subscriptions through your app-store account. You may ask us to access, correct, or delete personal information, subject to applicable exceptions. Depending on where you live, you may have additional rights, including the right to appeal a denied request. Contact us at [email protected]. We may verify your identity before completing a request.

You can manage notification categories in the app and push permissions in your device settings. You can choose not to submit Tutor questions or request generated examples. This does not prevent the app from retrieving AI-generated Daily Tips. Depending on applicable law, you may also have rights to a portable copy of your information, to restrict or object to processing, to withdraw consent where processing relies on consent, and to complain to a data-protection authority.

You can disable AI Tutor in the app’s preferences to stop future Tutor requests to OpenAI. Disabling Tutor does not delete previously saved conversations or monitoring records; you can request their deletion by contacting us. Withdrawing consent does not affect the lawfulness of processing carried out before withdrawal.

EEA and UK users may object, on grounds relating to their particular situation, to processing based on legitimate interests, including Tutor quality monitoring. We will stop that processing unless we demonstrate compelling legitimate grounds that override your rights and interests, or need it for legal claims. We normally respond to privacy-rights requests within one month; if a lawful extension is needed, we will explain the reason and timing. You may complain to the supervisory authority where you live or work in the EEA, or to the UK Information Commissioner’s Office, without contacting us first.

8. Children’s privacy

The Service is not directed to children under 13, and we do not knowingly collect personal information from children under 13. If you believe a child has provided personal information, contact us so we can investigate and take appropriate action. Additional age requirements may apply depending on location.

9. International processing

We and our service providers may process information in the United States and other countries whose data-protection laws may differ from those where you live. Where required, we use appropriate safeguards for international transfers. Depending on the recipient and transfer, these may include an applicable adequacy decision or approved contractual safeguards, such as the European Commission’s Standard Contractual Clauses and the UK Addendum or International Data Transfer Agreement. A provider’s hosting location alone does not determine the safeguards required for every transfer.

Contact us to request information about the safeguards applicable to your information or a copy of relevant transfer safeguards. AI features generate educational content; they are not used to make decisions about you with legal or similarly significant effects.

10. Changes to this policy

We may update this policy as the Service or legal requirements change. We will post the revised policy and update the effective date. If a change materially affects how we use information already collected, we will provide any additional notice required by law.

11. Contact us