Privacy Policy

Last updated: September 26, 2026

Fluo Inc., a Delaware corporation at 13109 Paloma Drive, Orlando, FL 32837, United States ("Fluo," "we," "us," or "our"), is the controller of the personal data described in this Privacy Policy. This policy explains how we collect, use, disclose, and safeguard your information when you use the Fluo mobile and web applications, our website at fluolearning.com, and related services (the "Service").

1. Information We Collect

Account Information

  • Email address and, if you provide one, a display name (when you create an account)
  • Authentication data from third-party sign-in providers (Apple, Google), limited to your name and email
  • Your language settings (the language you are learning and the language you read in) and your AI-features choice

Learning Data

  • Vocabulary progress, spaced-repetition data, and learning statistics
  • Practice session history and performance
  • Text you submit for translation, and the translation history the app keeps for you
  • Questions you ask the AI tutor, and the answers, which are kept in your account's AI history

Video and Content Data

  • Videos you watch, playback progress, ratings, skips, and saves
  • Subtitle interactions (words tapped, translations viewed)
  • Reports you submit about a video or its subtitles, and related moderation records
  • Feedback posts, comments, and votes you make on the in-app feedback board; posts and comments are shown to other signed-in users together with your display name
  • Videos you add from your own device, if you use that feature, and the subtitles generated for them

Fluo Friends

Fluo Friends is optional. You connect with someone only by sharing your personal friend code or invite link, or by entering theirs; there is no search, public directory, or messaging. If you use Friends, we process:

  • Your friend profile: your friend code (up to five letters taken from your display name followed by four random digits), and your progress-sharing and friend-request settings
  • Your friends, friend requests you send and receive (and whether they came from a code or an invite link), and the users you block
  • Activity cards generated from your progress (achievements, level-ups, and new friendships), the cheers you give and receive on them, and a weekly recap of words learned
  • A log of the friend codes you look up, used to stop people guessing codes

What your friends can see. Friends, and anyone who enters your friend code, see your display name, your chosen avatar outfit, and your level. While "Share my progress with friends" is on, they also see the language you are learning, and friends additionally see since when you have been learning it, your current and best streak, your word and known-word counts (including words learned this week and a three-month vocabulary chart), when you last practiced, whether you met your daily goal over the past week, your achievements and milestones, your activity cards, and your place in the weekly recap. Friends never see which individual words you know. Progress sharing is on by default, and you can turn it off at any time in Profile → Friends & privacy → "Share my progress with friends"; with it off, friends see only your name, outfit, and level, and no activity cards from you reach them. In the same screen you can choose who can send you requests ("Anyone with my code" or "No one"), reset your friend code, and manage blocked users. Blocking someone hides you from each other everywhere in Fluo.

Invitations and Referral Rewards

  • If you join with an invite code: the code you used, who invited you, the status and dates of the referral, and the days on which you open the app during the reward period (used to confirm that you came back). Redeeming an invite code also makes you and the person who invited you friends, with progress sharing on until you change it.
  • If you invite others: the people who joined with your code (shown to you by display name), the status of each referral, and the rewards you received.
  • Fraud prevention: when you redeem a code, our server takes the network part of your IP address (the first three parts of an IPv4 address or the first half of an IPv6 address), combines it with a secret key, and stores only a one-way SHA-256 hash of the result. We never store your raw IP address for this purpose. On iOS versions of Fluo that support it, the app may also send a one-time Apple DeviceCheck token; our server asks Apple whether the device has already redeemed an invite and marks it when it has, and we store only a SHA-256 hash of that token. DeviceCheck does not give us a device identifier.

Subscriptions and AI Credits

  • Your Fluo Pro status: plan, the store it was bought through, whether it is a free trial, and when it renews or expires, received from our subscription provider (RevenueCat). We do not receive your card or bank details.
  • A record of each AI credit you use (the type of AI action and when), and your device's time zone, which we use to count your daily credits and invite rewards by your local day

Device and Usage Information

  • Device type, operating system, and app version
  • Screens you view in the app and features you use, and pages you visit on our website
  • On our website: clicks on page elements, the page or link that referred you, and campaign parameters in the link you arrived from
  • Error and crash diagnostics
  • Your IP address, and an approximate location (such as country or city) derived from it

We do not collect your precise location, contacts, photos (other than a video you choose to add), microphone audio, or advertising identifiers.

Information received by third-party video players

Most videos in Fluo play inside the official embedded player of the platform that hosts them, principally TikTok. When such a player loads, that platform receives your IP address and standard device and browser information and may set cookies, under its own privacy policy (for TikTok, see tiktok.com/legal/privacy-policy). Fluo does not send the platform your Fluo account details. We cannot control what a platform does with the information its player collects.

2. How We Use Your Information and Our Legal Bases

  • To provide the Service (performance of our contract with you): your account, learning data, video interactions, and the content you submit.
  • To personalize your learning (contract): our adaptive algorithm and spaced-repetition scheduling use your progress and interaction history.
  • AI features (your consent): personalized practice sentences, on-demand translations, and the AI tutor run only if you opt in; you can withdraw in Profile settings at any time.
  • Generating subtitles (contract, and our legitimate interest in operating the Service): audio and on-screen text from videos, including videos you add, are processed by speech-recognition and translation services.
  • Fluo Friends (contract): showing your friend card, progress, and activity to the friends you connect with, according to your sharing settings.
  • Fluo Pro and AI credits (contract): counting your free AI credits, applying your subscription, trial, or invite reward, and restoring purchases on a new device.
  • Invite rewards and fraud prevention (our legitimate interest in keeping the referral program fair): confirming that an invite is eligible and enforcing its limits, using the hashed network and device information described in Section 1.
  • Analytics and diagnostics (our legitimate interest in understanding and improving the Service): usage events, device information, and error reports. Analytics are on by default, and the app does not currently have a separate analytics switch; you can object as described in Section 6, and on our website you can block the analytics cookie as described in Section 4.
  • Communicating with you (contract, legitimate interest): account emails, support replies, and, if you asked for them, product updates.
  • Safety, moderation, and legal compliance (legitimate interest, legal obligation): handling reports about videos, subtitles, and other users, honoring blocks, preventing abuse and fraud, responding to copyright notices, and keeping records the law requires.

We do not sell your personal information, and we do not use it for advertising or share it with advertisers.

3. Service Providers and Other Recipients

We use the following providers to operate Fluo. Each processes data on our behalf under a contract, except where noted.

  • Supabase — authentication and database hosting (United States)
  • Cloudflare — our API, storage and delivery of Fluo-hosted videos, thumbnails, and generated audio, and the website
  • Google Cloud Platform — audio extraction and speech-recognition processing for video subtitles
  • Google Gemini — AI text generation, translation, glossing, and search embeddings (AI features when you opt in; also subtitle processing)
  • OpenAI, xAI, and OpenRouter — additional AI model providers we may use for the same purposes; OpenRouter also provides speech recognition for some video audio
  • ElevenLabs — speech recognition for video audio and text-to-speech for study audio
  • MiniMax — text-to-speech for study audio
  • PostHog — product and website analytics and error diagnostics (United States); in the app, analytics events are linked to your Fluo account ID and email address
  • RevenueCat — subscription management. RevenueCat receives your Fluo account ID (a pseudonymous identifier, not your name or email), your purchase history, the store transaction identifiers for your purchases, and your subscription status, and it tells us whether you have Fluo Pro
  • Apple and Google — sign-in and, for subscriptions bought in the app, payment processing; they act as independent controllers under their own policies. On supported iOS versions, Apple also receives the DeviceCheck token described in Section 1
  • Stripe — card payment processing for subscriptions bought on our web app, where offered; Stripe processes your payment details under its own privacy policy, and we do not receive your full card number
  • TikTok and YouTube — providers of the embedded video players described in Section 1; they act as independent controllers under their own policies

Text you submit to AI features is sent to the AI provider only with the vocabulary and learning context needed to answer you. Your name, email, and account credentials are never sent to an AI provider. We use these providers through their business API services, whose terms restrict their use of the text to providing the response.

Other Fluo users. If you use Fluo Friends, the information described under "What your friends can see" in Section 1 is shown to your friends and to people who enter your friend code. If you joined with an invite code, the person who invited you sees your display name and the status of the referral. Feedback posts and comments are shown to other signed-in users as described in Section 1.

We may also disclose information when required by law, to respond to a valid legal process or a copyright notice, to protect the rights, safety, or property of Fluo, our users, or others, or in connection with a merger, acquisition, or sale of assets, in which case this policy continues to apply to your data.

4. Cookies and Similar Technologies

Our website uses a first-party analytics cookie and browser local storage, set by PostHog, to recognize your browser across visits and pages so we can measure how the site is used. This identifier lasts up to 12 months unless you clear it. We do not use advertising or cross-site tracking cookies. Session recording is switched off.

You can block or delete these cookies at any time through your browser settings; blocking them does not affect your ability to use the site. The mobile app does not use cookies; it stores an equivalent analytics identifier on your device, which is removed when you uninstall the app or delete your account. Embedded video players may set their own cookies, as described in Section 1.

5. Data Retention

  • Account and learning data: kept while your account is active. When you delete your account, we delete or anonymize your personal data within 30 days.
  • Translation history and AI tutor history: kept in your account until you delete the account.
  • Feedback posts and comments: kept for the community; on account deletion they are anonymized (your name and account link are removed).
  • Analytics: deleting your account also deletes your analytics profile and its events held by PostHog.
  • Videos you added: removed from the Service on account deletion.
  • Fluo Friends data: kept while your account is active. Removing a friend or turning off progress sharing stops them seeing your progress. Deleting your account deletes your friend profile and code, your friendships and friend requests, the users you blocked, your activity cards and any activity card that mentions you, the cheers you gave, and your friend-code lookup log. Entries in the lookup log older than a day are removed the next time you look up a code.
  • AI credits and Fluo Pro status: your credit records, your time zone, the record of days you opened the app for invite rewards, your Pro status, and any unused invite-reward days are deleted with your account.
  • Referral records: when either person in a referral deletes their account, we keep the referral record with the link to the deleted account removed. The record keeps the invite code that was used, the referral's status and dates, and the hashed network prefix and hashed DeviceCheck token described in Section 1. We keep it to prevent reward fraud (for example, claiming rewards again by deleting and re-creating accounts) and to enforce the program's limits, for as long as the referral program operates and the record is needed for that purpose.
  • Purchase records: deleting your Fluo account does not cancel a subscription bought through Apple, Google, or our web app; cancel it as described in our Terms of Service. RevenueCat, Apple, Google, and Stripe keep their own records of your purchases, which they and we may need to retain for accounting, tax, and refund purposes.
  • Records we must keep: we retain limited information where required for security, fraud prevention, copyright-notice handling, or legal compliance, including creator agreement records (which include the accepting person's IP address and browser information) for as long as the related content or agreement is relevant.

6. Your Rights

Depending on where you live, you may have the following rights regarding your personal data:

  • Access — request a copy of the personal data we hold about you
  • Correction — request that we correct inaccurate or incomplete data; you can edit your display name and language settings in the app
  • Control what friends see — in Profile → Friends & privacy, turn "Share my progress with friends" off, stop new friend requests, reset your friend code, or manage blocked users; you can also remove or block a friend from their profile
  • Deletion — delete your account and data in the app (Profile → Account & data → Delete Account), or via our account deletion page
  • Portability — request a machine-readable copy of your data
  • Objection and restriction — object to, or ask us to restrict, processing based on our legitimate interests
  • Withdraw consent — turn AI features off in Profile settings at any time; withdrawal does not affect processing that already happened
  • Complain — lodge a complaint with your local data-protection authority; in the United Kingdom that is the Information Commissioner's Office

To exercise any of these rights, contact us at support@fluolearning.com from the email address on your account. We respond within 30 days (45 days where U.S. state law allows), and we do not discriminate against you for exercising your rights. If we decline a request, you may appeal by replying to our response, and we will explain the outcome.

7. Data Security

We implement appropriate technical and organizational measures to protect your personal information, including encryption in transit (TLS), signed authentication tokens, row-level access controls in our database, and restricted administrative access. However, no method of transmission over the Internet or electronic storage is 100% secure, and we cannot guarantee absolute security.

8. Children's Privacy

Fluo is not intended for children under 13, or under the higher minimum age that applies in your country for consenting to online services. We do not knowingly collect personal information from children below that age. If we learn that we have collected personal data from such a child, we delete the account and its data promptly. If you believe a child has provided us with personal information, please contact us at support@fluolearning.com.

9. International Data Transfers

Fluo is based in the United States, and our providers process data in the United States and other countries whose data protection laws may differ from those of your country. Where we transfer personal data from the European Economic Area, the United Kingdom, or Switzerland, we rely on providers that are certified under the EU-U.S. Data Privacy Framework (and its UK and Swiss extensions) or on standard contractual clauses approved by the European Commission and the UK, together with additional safeguards where appropriate. You can ask us for details of these safeguards.

10. Changes to This Policy

We may update this Privacy Policy from time to time. When we make changes, we will revise the "Last updated" date at the top of this page. If the changes are material, we will notify you through the app or by email before they take effect.

11. Contact Us

If you have questions or concerns about this Privacy Policy or our data practices, contact us at:

Fluo Inc.
13109 Paloma Drive
Orlando, FL 32837, United States
support@fluolearning.com