Privacy Policy
Effective date: July 29, 2026 · Last updated: July 29, 2026
1. Who we are
Fude ("Fude", "we", "us") is an app for learning to write Japanese kana (hiragana and katakana) stroke by stroke. The data controller responsible for your information is Karim Ghezali. Contact: hello@fudejapanese.com. Website: https://fudejapanese.com. If you are in the EU/EEA and have questions about your data, contact us at the address above.
2. Our approach to your data
Fude is built to be local-first. Fude does not require an account. You do not create a username or password, and we do not ask for your name or email to use the app. Your learning progress and settings are stored locally on your device, not on our servers. We collect the minimum needed to make the app work, keep it stable, and understand — anonymously — how the app is used so we can improve it.
3. What data is processed, and where
a) Data stored only on your device (we never receive it)
Learning progress (which kana you have practised, your fading level per character, review state, completion history) and settings. This information stays on your device and is removed if you delete the app.
b) iCloud sync (Apple)
If you are signed in to iCloud, your progress and settings are synced between your own Apple devices through Apple's iCloud key-value storage. This data lives in your iCloud account, not on our servers: we cannot read it, and we never receive it. It is covered by Apple's privacy policy. You can turn iCloud off for Fude in iOS Settings, in which case the app keeps everything on the device only and works exactly the same.
c) Anonymous usage analytics (PostHog)
Analytics are off by default and consent-gated: nothing is collected — the analytics client is not even created — until you opt in, and you can opt out again at any time in Settings.
When enabled, the app sends one anonymous event per practice attempt, so we can calibrate the handwriting recognition: the character practised and its codepoint, the practice group, mode and fading level; whether the attempt was accepted, which check failed if not, and the recognition scores and thresholds the engine compared — overall and per individual stroke (shape, direction, curvature, proportion, position), with each stroke's pass/fail status; counters and timing: attempt number, strokes drawn versus expected, duration, whether a hint was used, and whether it was your first attempt at that character.
We also send an event when a character is abandoned after repeated failures. In TestFlight builds you can flag an attempt you believe was judged wrongly, which re-sends the same values marked as disputed.
Your handwriting never leaves your device. Only numbers and pass/fail results are sent — no stroke coordinates, no traces, no images, nothing from which your writing could be reconstructed.
This data carries a random, app-generated identifier, never your name, email, or an account. It is hosted in the European Union, is not used to track you across other apps or websites, and is never sold.
This website uses no analytics, tracking scripts or advertising pixels. It loads web fonts from Google Fonts, which receives your IP address for that request only.
d) Crash and error reporting (Sentry)
To keep the app stable, we use Sentry to collect crash and error diagnostics from the app, stored in the European Union. Crash reports contain technical information (error details, device and OS version, app state at the time of the crash) and do not identify you personally. The app also reports when it becomes unresponsive or is terminated by the system, so we can identify and fix these problems.
e) Purchases (Apple)
Fude offers a free tier and a one-time in-app purchase to unlock full content. Purchases are processed by Apple through the App Store. We do not receive or store your payment details. We may receive anonymised, aggregate purchase information from Apple, never your payment method or identity.
4. Legal bases (GDPR)
For users in the EU/EEA, we rely on: consent (for usage analytics — you can withdraw at any time); legitimate interests (for crash/error diagnostics needed to keep the app secure and functioning); and performance of a service (to provide the learning features you request).
5. Who we share data with
We do not sell your data. We share data only with the service providers that operate the app's infrastructure, strictly to provide the service: PostHog (EU) for anonymous analytics, Sentry (EU) for crash diagnostics, and Apple for app distribution and in-app purchases. These providers act as our processors under contract. On-device data is not shared with them.
6. International transfers
We host analytics and diagnostics in the European Union. Where any provider processes data outside the EU/EEA, we rely on appropriate safeguards such as the European Commission's Standard Contractual Clauses.
7. Data retention
On-device data (progress, settings) is kept until you delete it in the app or uninstall the app. Analytics and crash data are retained only as long as needed for the purposes above, in line with our providers' standard retention periods, then deleted or anonymised.
8. Your rights
Subject to applicable law (including the GDPR), you have the right to access, correct, delete, restrict, or object to the processing of your personal data, and to data portability. Because most of your data lives only on your device, you can exercise much of this directly: uninstall the app to remove local data. For analytics or crash data, contact hello@fudejapanese.com and we will action your request. You may also lodge a complaint with your local data protection authority (in France, the CNIL).
9. Children
Fude is suitable for learners of all ages but is not directed to children under 16, and we do not knowingly collect data from them. The analytics and crash data described above contain no personal identifiers. If you believe a child's data has been collected in error, contact us.
10. Security
We use reputable providers and reasonable technical measures to protect data. No method of transmission or storage is completely secure, but keeping your learning data on your device by default reduces exposure.
11. Third-party content
Fude uses stroke-order data from KanjiVG (© Ulrich Apel), licensed under CC BY-SA 3.0. This is embedded reference data and does not involve any collection of your information. The derived stroke data we use is published separately under CC BY-SA 3.0 at https://github.com/karimghezali/fude-kana-data.
12. Changes to this policy
We may update this policy as the app evolves. We will post the updated version here and change the "Last updated" date. Material changes will be communicated in-app where appropriate.
13. Contact
Questions about privacy: hello@fudejapanese.com