Privacy Policy

How flangu collects, uses, discloses, and protects information when you use the flangu mobile app on iOS and Android, and the flangu.app website.

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Effective date: July 31, 2026 Last updated: August 15, 2026

This Privacy Policy explains how flangu ("flangu," "we," "us," or "our") collects, uses, discloses, and protects information when you use the flangu mobile application (the "App") on iOS and Android, and the flangu website at flangu.app (the "Site").

flangu is operated by an individual developer trading as ravdar ("we," "us"). If you have questions about this policy or your data, contact:

Email: contact@flangu.com

By using the App, you agree to the collection and use of information in accordance with this policy. If you do not agree, please do not use the App.

1. Information We Collect

We collect the following categories of information:

1.1 Account information

When you create an account, we collect:

Email address
Password (stored as a salted, irreversible hash — we never store or can view your plaintext password)
If you sign in with Google Sign-In: your Google account email and basic profile identifiers, as provided to us by Google, used to create and authenticate your account

1.2 Content you create

Words, phrases, and text you enter or translate, and the flashcards, decks, and study material generated from them
Linguistic metadata generated for your cards (translations, synonyms, definitions, example sentences, pronunciation, and — where applicable — AI-generated vocabulary images)
Optional feedback or support messages you submit to us, together with the email address you provide with them

1.3 Learning and usage data

Your flashcard review history and ratings (e.g., Again/Hard/Good/Easy)
Spaced-repetition scheduling data computed for your cards (e.g., stability, difficulty, retrievability, due dates) under the FSRS-6 algorithm
Study statistics, streaks, and progress data
App settings and preferences (e.g., desired retention, appearance, notification preferences)

1.4 Personal Tutor conversations (Pro feature)

If you use the Personal Tutor chat assistant, we process the messages you send and the associated flashcard content (front/back word, language pair) in order to generate a response. Tutor conversations are scoped to a single card and are not retained as a persistent chat history once a session ends.

1.5 Subscription and purchase information

In-app purchases (flangu Pro) are processed through Apple's App Store or Google Play's billing systems and managed via RevenueCat, our subscription management provider. We (and RevenueCat) receive transaction identifiers, purchase/renewal/cancellation status, and entitlement status. We do not receive or store your payment card details — these are handled entirely by Apple or Google.

1.6 Device and technical information

Device identifiers, device model, and operating system version (used to support the app and for push notification delivery)
Push notification token, if you enable notifications
IP address, request timestamps, and basic technical logs generated when the App communicates with our servers
Crash reports and error diagnostics, collected automatically via Sentry, which may include device information, app state, and stack traces at the time of a crash or error. We do not intentionally include flashcard content or account credentials in these reports.

1.7 Information we do not collect

We do not collect precise (GPS) location data, contacts, photos/camera roll access, health data, or biometric data. The App contains no advertising and does not use advertising SDKs or ad identifiers for tracking.

1.8 Waitlist signups (Website)

If flangu has not yet launched and you join the pre-launch waitlist on the Site, we collect the email address you submit, which of the waitlist forms on the page you used, and the date and time of your signup. This is collected only if you choose to join the waitlist — see Section 2 for how it's used and Section 5 for how long it's kept.

2. How We Use Your Information

We use the information described above to:

Create and maintain your account, and authenticate you
Generate flashcards, translations, audio pronunciations, and AI-generated linguistic metadata and vocabulary images
Schedule your flashcard reviews using the FSRS-6 spaced repetition algorithm
Operate the Personal Tutor assistant (Pro feature)
Process and manage your flangu Pro subscription
Sync your data across your devices and provide backups
Send you service-related communications (e.g., email verification, password reset, account notices) and, if enabled, study reminder push notifications
Diagnose crashes, fix bugs, and maintain the security and reliability of the App
Respond to support requests and feedback
Notify you when the app launches, if you joined the pre-launch waitlist
Protect against fraud, abuse, and automated (bot) activity
Comply with legal obligations

We do not sell your personal information, and we do not use your data for third-party advertising.

We share information only as necessary to operate the App, with the following categories of service providers, each acting under their own privacy terms and, where applicable, contractual data-protection obligations to us:

Category	Provider(s)	Purpose
Authentication	Google Sign-In	Optional sign-in method
Translation & AI content generation	Google Cloud Translate, Google Cloud (Gemini) Generative AI	Generating translations and linguistic metadata
Text-to-speech audio	Google Cloud Text-to-Speech; on-device speech engine (fallback / free tier)	Generating spoken pronunciation audio
Cloud storage	Google Cloud Storage	Storing generated vocabulary images and media assets
Subscriptions & payments	RevenueCat; Apple App Store; Google Play Billing	Processing and managing flangu Pro purchases
Email delivery	SendGrid; Amazon SES	Sending verification, password-reset, account-related, and waitlist notification emails
Bot / abuse protection	Cloudflare Turnstile	Distinguishing human users from automated traffic
Error monitoring	Sentry	Crash and error diagnostics
Infrastructure & hosting	Our cloud hosting and database providers	Running the App's backend and storing your data securely
Website analytics	Google Analytics	Aggregate website traffic statistics on the Site (only with your consent — see Section 4)

We may also disclose information:

To comply with a legal obligation, court order, or valid governmental request
To enforce our terms, protect our rights, or protect the safety of our users or the public
In connection with a merger, acquisition, or sale of assets, in which case we will notify you before your data becomes subject to a different privacy policy

We do not share your flashcard content, account details, or usage data with third parties for their own marketing purposes.

4. Cookies and Similar Technologies (Website)

This section applies to the flangu website at flangu.app (the "Site"), including this page, our documentation, and our blog. It does not apply to the App, which does not use browser cookies.

Cookie / storage	Purpose	Type	Lifetime
`sessionid`	Keeps you signed in during a session	Strictly necessary	Up to 14 days
`csrftoken`	Protects forms against cross-site request forgery	Strictly necessary	1 year
`cookie_consent`	Remembers your cookie choice	Strictly necessary	180 days
`__cf_bm` (Cloudflare Turnstile)	Distinguishes humans from bots on the registration and waitlist forms	Strictly necessary	30 minutes
`htmx-history-cache` (browser local storage)	Caches pages for faster back/forward navigation on our documentation and blog	Functional	Until browser storage is cleared
`_ga`, `_ga_T7L54E48Q3` (Google Analytics)	Aggregate traffic and usage statistics for the Site	Analytics — requires your consent	Up to 2 years

Strictly necessary and functional cookies run automatically because the Site cannot work properly without them. The Google Analytics cookies are set only after you accept them in the cookie banner shown on your first visit.

You can change or withdraw your cookie choice at any time using the "Cookie settings" link in the Site's footer. Withdrawing consent removes the Google Analytics cookies from your browser. See Google's Privacy Policy and how Google uses information from sites that use its services for more on Google Analytics.

5. Data Storage and Retention

Your account and its associated data (flashcards, decks, review history, statistics, settings) are stored on our servers and retained for as long as your account remains active.
A local copy of your flashcards and review data is also stored on your device to support offline studying, and is synced to our servers when you have an internet connection.
Crash and error diagnostics collected via Sentry are retained according to Sentry's standard retention periods, which are generally shorter than account data retention.
When translated words and their generated metadata are identical across users (e.g., the same common word translated by many learners), we may maintain a shared, non-personal translation cache to improve performance. This cache is not linked to your identity and is not affected by deletion of your account.
Waitlist signups are kept until the launch-announcement email has been sent, after which the entries are deleted.

Account deletion

You can permanently delete your account and all associated personal data at any time from within the App (Settings → delete account). Deletion is immediate and irreversible: it permanently removes your profile, decks, flashcards, review history, statistics, settings, subscription records, and linked sign-in credentials from our systems. We recommend downloading or noting any information you wish to keep before deleting your account, as it cannot be recovered afterward.

6. Data Security

We use industry-standard measures to protect your information, including encrypted transmission (HTTPS/TLS) between the App and our servers, hashed password storage, and access controls on our infrastructure. However, no method of electronic storage or transmission is 100% secure, and we cannot guarantee absolute security.

7. International Data Transfers

Our servers and service providers may process and store data in countries other than your own, including the United States. Where we transfer personal data from the European Economic Area (EEA), United Kingdom, or Switzerland to a country without an adequacy decision, we rely on appropriate safeguards, such as Standard Contractual Clauses, as required by applicable law.

8. Your Privacy Rights

8.1 All users

Regardless of location, you can at any time:

Access and update your account information within the App
Delete individual flashcards, decks, or your entire account from within the App
Opt out of push notifications via the App's settings or your device's system settings
Contact us at contact@flangu.com with any privacy request

If you are located in the EEA, UK, or Switzerland, you have the right to:

Access the personal data we hold about you
Rectify inaccurate personal data
Erase your personal data ("right to be forgotten")
Restrict or object to certain processing
Data portability (receive your data in a structured, machine-readable format)
Withdraw consent at any time, where processing is based on consent
Lodge a complaint with your local data protection supervisory authority

Our legal bases for processing your data are: performance of a contract (providing the App's core functionality), your consent (e.g., optional notifications), our legitimate interests (e.g., security, fraud prevention, service improvement), and compliance with legal obligations.

8.3 California residents (CCPA/CPRA)

If you are a California resident, you have the right to:

Know what personal information we collect, use, and disclose
Request deletion of your personal information
Correct inaccurate personal information
Opt out of the "sale" or "sharing" of personal information — we do not sell or share your personal information as those terms are defined under the CCPA/CPRA
Non-discrimination for exercising your privacy rights

To exercise any of these rights, contact us at contact@flangu.com. We may need to verify your identity before fulfilling certain requests.

8.4 Other jurisdictions

If you reside in a jurisdiction with its own data protection framework (e.g., Canada's PIPEDA, Brazil's LGPD, or Australia's Privacy Act), we will honor requests consistent with your applicable local rights. Contact us at contact@flangu.com to make a request.

9. Children's Privacy

flangu is a general-audience app and is not directed at children under the age of 13 (or the equivalent minimum age in your jurisdiction, e.g., 16 in certain EEA member states). We do not knowingly collect personal information from children under this age. If you believe a child has provided us with personal information, please contact us at contact@flangu.com and we will promptly delete it.

10. Third-Party Links and Services

The App and Site integrate with third-party services described in Section 3. Those providers' own privacy policies govern their handling of information they process on our behalf or independently:

11. Changes to This Policy

We may update this Privacy Policy from time to time to reflect changes in our practices or for legal, operational, or regulatory reasons. If we make material changes, we will notify you through the App or by other reasonable means before the change takes effect. The "Last updated" date at the top of this policy indicates when it was most recently revised. Your continued use of the App after a change takes effect constitutes acceptance of the revised policy.

12. Contact Us

If you have questions, concerns, or requests regarding this Privacy Policy or your personal data, contact: