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Privacy Policy

Last updated: August 18, 2026

This Privacy Policy explains how Tsunagi ("Tsunagi," "the App," "we," "us") collects, uses, stores, and shares information when you use the Tsunagi mobile application on Android and iOS.

Tsunagi is developed and operated by Kutay Kurnaz, an individual developer based in Turkey (not a registered company). For any privacy question, contact:

Email: gazi.kutay.kurnaz@gmail.com

By using Tsunagi, you agree to the collection and use of information as described in this Privacy Policy. If you do not agree, please do not use the App.

1. Summary: Fully Offline by Design

Tsunagi is a fully offline flashcard / spaced-repetition app. There is no account creation or sign-in, and no AI-powered features. Your content — notes, flashcards, folders, decks, study history, imported PDFs, and any photos, videos, audio, or 3D models you attach — is stored only on your device, in a local database. We never see it, and it never leaves your device.

The only outside service Tsunagi uses is PostHog, for basic, anonymous app analytics (§ 2.2).

2. Information We Collect

2.1 Your content (notes, flashcards, study data, media)

Your notes, flashcards, decks, folders, review/study history, imported PDFs, highlights, and any images, audio, video, or 3D models you attach are stored locally on your device only. This content is never transmitted to us or to any third party.

This includes media you capture with your device's camera or microphone: if you grant Tsunagi camera, microphone, or photo library access to attach a photo, video, or audio recording to a flashcard, that file is saved directly to the App's local storage on your device and processed entirely on-device. We do not receive a copy of it.

2.2 Usage / analytics data

We use PostHog (hosted in the EU) for basic, anonymous app analytics. This includes:

Automatically collected data: app lifecycle events (e.g., app opened/backgrounded) and standard technical metadata PostHog collects for any event — an anonymous device/session identifier, coarse device and OS information, and an approximate location derived from your IP address.
A small number of custom, name-only events: we send an event when a flashcard is created, when a study session finishes, and when the card browser screen is opened. Each event carries only its name and PostHog's own automatic metadata above — we never attach the content of your note, your study results, or any other property to these events.

We do not link this analytics data to your identity: our PostHog configuration explicitly disables person-profile creation, so events are recorded as anonymous, unidentified activity. There is currently no in-app setting to disable this analytics collection.

2.3 Information we do not collect

We do not collect your name, email, contacts, precise GPS location, phone number, government ID, biometric data, or advertising identifiers. We do not run advertising or ad-tracking SDKs, and we do not have any account system — Tsunagi cannot be signed into and does not ask you to create an account.

3. How We Use Information

We use the information above to:

Operate, maintain, and improve the App (including diagnosing issues and understanding aggregate, anonymous feature usage through analytics);
Comply with legal obligations and enforce our Terms of Service.

We do not sell your personal data, and we do not share it with third parties for their own marketing purposes.

4. Third-Party Service Providers

We share limited information with the following service provider, acting as a data processor on our behalf:

Provider	Purpose	Data involved
PostHog (EU-hosted)	App analytics	Anonymous device/session ID, app lifecycle events, the 3 custom event names described in § 2.2, coarse device/IP-derived location

We require our service providers to protect your information and only use it to provide services to us, except as described in this policy.

5. Data Storage and Security

Your content is stored in a local database on your device. It is protected by your device's operating system app-sandboxing (on Android, other apps cannot read Tsunagi's data without root access; similarly on iOS). Tsunagi does not currently add its own additional encryption layer on top of this — we recommend enabling your device's screen lock and full-disk encryption (on by default on most modern Android and iOS devices) for extra protection, especially if your device could be lost or stolen.
No method of electronic storage or transmission is 100% secure. We cannot guarantee absolute security, but we take reasonable measures to protect your information.

6. Data Retention

Your content stays on your device until you delete it or uninstall the App. We do not hold a copy anywhere else. Uninstalling the App removes all locally stored content from your device.

Anonymous analytics data (§ 2.2) is retained by PostHog according to their own retention policy; because it is not linked to your identity, we have no way to identify or extract an individual person's analytics activity from it.

7. Your Rights

Depending on where you live, you may have rights regarding personal data processed about you. If you are in Turkey, these rights are set out in Article 11 of Law No. 6698 on the Protection of Personal Data (KVKK); if you are in the European Economic Area, similar rights are set out under the GDPR. Because Tsunagi has no account system and stores your content only on your device, the only data we process is the anonymous analytics data described in § 2.2 — which, being anonymous and unlinked to any identity, cannot be tied back to a specific person to fulfill an individual access/deletion request.

If you have a privacy question or concern regardless of the above, email gazi.kutay.kurnaz@gmail.com and we will respond within the timeframe required by applicable law (generally within 30 days under KVKK).

8. Children's Privacy

Tsunagi is intended for users who are at least 18 years old (or the age of majority in your country, if higher), and it is not directed at children. We do not knowingly collect personal data from children. If you believe a child has provided us with personal data, contact us and we will delete it.

9. International Users

Tsunagi is operated from Turkey. PostHog (§ 4) processes analytics data in the European Union. By using the App, you consent to this processing.

10. Future Changes

We may add new features to Tsunagi in the future — for example, optional account sign-in or optional cloud sync. If we do, we will update this Privacy Policy in advance to describe exactly what is collected, how it's used, and how you can control it.

We will update the "Last updated" date above whenever this policy changes and, for material changes, notify you in-app or via the app store listing before the change takes effect where required by law.

11. Contact Us

Questions about this Privacy Policy or your data:

Gazi Kutay KURNAZ
Email: gazi.kutay.kurnaz@gmail.com