Privacy Policy

Nikola Artukov, trading as LingoBlend ("we," "our," or "us"), operates the LingoBlend mobile application, the LingoBlend Chrome browser extension, and the website at lingoblend.app (together, the "Service"). This Privacy Policy explains what information we collect, why, who we share it with, and what rights you have.

We have tried to make this document specific rather than reassuring. Where a practice is unusual — for example, that text you submit for blending is sent to third-party AI providers — we say so plainly.

1. Data Controller

The data controller responsible for your personal data is:

Nikola Artukov (sole trader)
Svetog Dimitrija, Sremska Mitrovica, Serbia
Email: support@lingoblend.app

We are established in Serbia and are subject to the Serbian Law on Personal Data Protection (Zakon o zaštiti podataka o ličnosti). Because we offer the Service to users in the European Economic Area and the United Kingdom, the EU GDPR and UK GDPR also apply to that processing.

2. Information We Collect

Account information

• Email address
• First name and username (your username is visible to other signed-in users, and is used to enforce uniqueness)
• Password — stored only in hashed form by Firebase Authentication. We never see or store your plain-text password.
• Language preferences (target language and known language), your daily goal, and your self-assessed level in each language you learn (used to personalize blending)
• Subscription status

If you sign in with Apple or Google, we receive your name and email address from that provider. We never receive your Apple or Google password. If you use Apple's "Hide My Email," we only ever see the relay address Apple gives us.

Content you create or submit

• Saved dictionary words, custom translations, and custom phrases
• Word lists you create or import, including imported CSV/text files
• Text you submit for blending or guided reading — pasted text, uploaded files (including PDF and EPUB documents), and web page addresses you ask us to import. We retain both the original text and the processed result so you can re-blend and resume reading.
• Photographs you submit for text extraction (OCR import)
• Photographs you choose from your camera roll to associate with a saved word. These are uploaded to and stored permanently in Firebase Storage until you remove them or delete your account.
• Personal mnemonic notes ("memory tricks") you write against a word
• Your reason for learning the language, if you answer that optional question. It is shown back to you at milestones and is never used for advertising or shared with anyone.
• Bookmarks and reading positions
• Learning progress, spaced-repetition history, game sessions, daily practice data, and time spent reading

Device and technical data

• Push notification tokens, used solely to deliver notifications you opted into
• Your device's time zone (for example Europe/Belgrade) and a derived delivery hour. We use these only to send a notification at the local time you chose, rather than at one fixed global instant. Without them a reminder set for 18:00 would arrive in the middle of the night for most of the world.
• The routine you name as your reading anchor, if you choose one during setup (for example "after my morning coffee"). It is used verbatim as the text of your own reminder and for nothing else, and is deleted along with your other notification data when you turn notifications off.
• The date you last practised or read, recorded at most once per calendar day. It determines your streak and whether we send a re-engagement notification.
• Device platform (iOS or Android) and app version
• Your device's region setting, read locally and only to determine whether we must ask for your analytics consent before collecting anything. It is not transmitted for that purpose.
• Usage counters we keep to enforce free-tier limits and prevent abuse (for example, how many photo imports or blends you have used this month)

The time zone, delivery hour and routine anchor above exist only to support notifications, and rest on the same consent as the notification itself (Article 6(1)(a) GDPR). If you turn notifications off, we delete them along with your push token. Withdrawing consent is one toggle in Settings and never costs you access to anything else in the app.

Analytics and session recording

If you allow it, we use PostHog to collect product analytics: which screens you open, which features you use, and app lifecycle events. This includes session recordings — replays of your interaction with the app.

To be accurate about what this is: analytics events are linked to your account identifier, so this data is pseudonymous rather than anonymous. Text you type into input fields and images are masked in session recordings, but other on-screen text is not. We do not send the words you save, your search terms, or the content of your blended texts to PostHog.

Your control. In the EEA, the UK, and Switzerland, analytics and session recording are off until you explicitly turn them on, and we ask you once. Everywhere else they are on by default. In both cases you can change your choice at any time in Settings → Privacy → Share Usage Data, and turning it off stops collection immediately.

Chrome extension

If you use the LingoBlend Chrome extension, we additionally process:

• Text you select on a web page at the moment you choose to save it as a word
• A short-lived authentication token, together with your account identifier and email address, held in encrypted browser session storage and cleared automatically when you close the browser
• A long-lived sign-in (refresh) token held in browser local storage, so the extension can stay signed in across browser restarts without asking you to sign in again. It is deleted when you sign out.
• Your language pair (for example "en-es"), your blending settings, and your subscription status, cached in browser local storage so the extension does not have to re-fetch them. These are removed when you sign out.

Page access. Saving a word uses the activeTab permission, which grants access to a page solely at the moment you invoke the extension on it. The optional page blending feature needs broader access, so the extension asks for permission to read pages at the moment you switch blending on — never at install. If you never turn blending on, the extension never reads a page you have not explicitly acted on. You can withdraw that access at any time by switching blending off, or from Chrome's extension settings.

What blending does with page text. When blending is on, the extension reads the visible text of pages you open in order to choose words and substitute them. That text is translated entirely on your own device using Chrome's built-in translator. No page content, page address, or browsing history is ever sent to us or to any third party. The text is processed in the page and is not stored anywhere. Blending is skipped on editors and messaging tools (including Gmail, Google Docs, Notion, Slack and similar), and inside text boxes, form fields and code blocks. You can also switch it off for individual sites.

The only page text that reaches our servers is a single word you explicitly choose to save — either by right-clicking your selection, or by tapping a blended word and choosing to save it. We do not track your browsing history.

Website

The lingoblend.app website does not use analytics, advertising, or tracking cookies, and sets no cookie banner because it sets no such cookies. One endpoint on the site receives an identity token from Apple as part of the extension's Apple Sign-In flow; it passes that token straight back to the extension and does not store it.

3. Legal Basis for Processing (GDPR)

If you are in the EEA or the UK, we process your data on the following bases:

• Contract performance (Art. 6(1)(b)): everything needed to actually provide the Service — your account, dictionary, text blending and guided reading, translations, games, stories, audio pronunciation, and progress tracking.
• Legitimate interest (Art. 6(1)(f)): keeping the Service secure, enforcing usage limits, and preventing abuse. You may object to this under Art. 21.
• Consent (Art. 6(1)(a)): analytics and session recording, and optional notifications (daily reminders, streak warnings, tips and updates). You can withdraw either at any time — analytics in Settings → Privacy, notifications in Settings → Notifications — and withdrawing is as easy as giving it. Withdrawal does not affect processing carried out beforehand.

4. How We Use Your Information

• Provide and personalize the Service: deliver the dictionary, text blending, guided reading, games, and stories for your language pair.
• Process content you submit: send your text, words, photographs, and documents to the translation, OCR, speech, and AI services listed in Section 5.
• Track learning progress: maintain your spaced-repetition schedule, game history, streaks, and goals.
• Send notifications you have opted into, and service messages such as password resets and email verification.
• Improve the Service: with your consent, analyze usage to fix bugs and prioritize features.

We do not use your data for advertising, we do not build advertising profiles, and we do not make automated decisions that produce legal or similarly significant effects.

5. Third-Party Services

The Service depends on the providers below. Each receives only what its function requires. Where a provider processes personal data on our behalf, it does so as a processor under its own data processing terms, which impose confidentiality and security obligations comparable to our own.

When you ask us to import a web page, our server fetches that address on your behalf. The website you named will see a request from our server, not from you.

We do not sell your personal information, we do not share it for cross-context behavioral advertising, and we do not disclose it to third parties for their own marketing.

6. AI Processing of Your Content

Several features work by sending your content to third-party AI providers. This is worth stating clearly because it is the least obvious thing the Service does:

• Text you paste, upload, or import for blending or guided reading is transmitted in full to Google (Gemini). If Gemini is unavailable, the same text is sent to Anthropic (Claude) instead. A blend can be up to 10,000 words.
• Individual saved words are sent to Gemini for base-form detection, conjugation tables, example sentences, and the Word of the Day.
• We do not send your account identifier or email address to these providers alongside your content.

We use these providers' paid API tiers, under terms that do not permit your content to be used to train their models. We do not train any model of our own on your content.

7. Data Storage and Retention

• Account and content: stored in Google Cloud Firestore and Firebase Storage, and retained while your account is active. If you do not sign in for 24 consecutive months, we may delete the account and its content after giving you notice by email.
• Analytics: retained by PostHog for up to 12 months, and only if you have consented.
• Diagnostic logs: retained in Google Cloud Logging for up to 30 days, then deleted automatically.
• Usage counters: reset monthly; historical counters are not retained.
• On-device caches: translations, example sentences, audio, and images are cached on your device and cleared when you sign out or delete your account.
• Account deletion: you can delete your account in the app under Account Settings, or by emailing us. This immediately and permanently removes your profile, all subcollections of your data, your uploaded images, and your authentication record. We instruct our processors to delete the data they hold, and residual copies in backups and diagnostic logs are purged on their own cycles within 30 days.

8. Data Security

• All data in transit is encrypted using HTTPS/TLS.
• All API keys and secrets are held server-side in Firebase Secret Manager and are never shipped in the app.
• Access to your stored data is enforced by Firebase Authentication together with Firestore and Firebase Storage security rules, which restrict your account data and your uploaded images to your own account. Your username is the exception: it is readable by other signed-in users so that usernames can be unique.
• Passwords are hashed by Firebase Authentication and never stored in plain text.

No method of electronic storage or transmission is completely secure. We cannot guarantee absolute security, but if a breach affects your personal data and poses a risk to you, we will notify you and the relevant supervisory authority as required by law.

9. Your Rights and Choices

Everyone

• Access and correction: view and update your details in Account settings.
• Deletion: delete your account and all associated data from within the app.
• Analytics: turn analytics and session recording on or off at any time in Settings → Privacy.
• Notifications: opt out at any time in Settings → Notifications or in your device settings.
• Data export: request a copy of your data in a machine-readable format by emailing us.

EEA and UK residents (GDPR)

You additionally have the right to:

• Restrict processing in certain circumstances.
• Object to processing based on legitimate interest.
• Withdraw consent at any time, without affecting prior processing.
• Data portability for data you provided to us.
• Lodge a complaint with your national data protection authority, or with the Serbian Commissioner for Information of Public Importance and Personal Data Protection (Poverenik), which supervises us as a Serbian controller.

We respond to rights requests without undue delay and within one month, as GDPR requires. Where a request is complex we may extend this by two further months and will tell you if we do.

California residents (CCPA/CPRA)

In the past 12 months we have collected the following statutory categories of personal information, for the business purposes described in Section 4, from you directly and from the sign-in provider you chose:

• Identifiers: name, username, email address, account identifier, push token
• Commercial information: subscription and purchase history
• Internet or network activity: feature usage, screen views, and session recordings, if you consented
• Visual information: photographs you upload
• Other user-generated content: the text, words, and notes described in Section 2

Retention periods for each category are set out in Section 7. The categories of third parties we disclose to are listed in Section 5. You have the right to know, to delete, to correct, to limit the use of sensitive personal information (we do not collect any), and not to be discriminated against for exercising these rights — we do not offer different pricing, service quality, or feature access on that basis. We do not sell or share personal information as those terms are defined by the CPRA, and we have not done so in the past 12 months. You may use an authorized agent to make a request; we will ask for proof of their authority.

To exercise any right, email support@lingoblend.app. We may need to verify your identity against your account before acting.

10. Children's Privacy

LingoBlend is a general-audience product intended for users aged 13 and over, or 16 and over in the EEA. It is not directed to children, and we do not knowingly collect personal information from children below those ages. If you are a parent or guardian and believe your child has given us personal information, email support@lingoblend.app and we will delete the account and its data promptly.

11. International Data Transfers

We are established in Serbia. Depending on the service, your data may be processed in:

• United States: Google (Firebase, Firestore, Cloud Functions, Cloud Storage, Cloud Logging, Cloud Vision, Gemini, Text-to-Speech), Anthropic, PostHog, Expo, Resend, RevenueCat
• European Union: our self-hosted LibreTranslate server in Helsinki, Finland
• Germany: Pixabay
• Other regions: Microsoft Azure Translator may process data in the region nearest to you; Tatoeba is operated from France

Where personal data is transferred out of the EEA or the UK, we rely on the European Commission's Standard Contractual Clauses (and the UK International Data Transfer Addendum where applicable) as incorporated into our providers' data processing terms, together with the safeguards those providers apply.

12. Changes to This Policy

We may update this Policy. If a change is material we will tell you in the app or by email before it takes effect, and we will update the date at the top. Where a change requires your consent, we will ask for it rather than assume it.

13. Contact Us

Questions, requests, or complaints about this Policy or our data practices:

Nikola Artukov
Svetog Dimitrija, Sremska Mitrovica, Serbia
support@lingoblend.app