Tanuki

Privacy Policy

Last updated: July 28, 2026

In brief: Tanuki stores your learning progress on your device first, so the app is fully usable offline. An anonymous account (a random identifier, with no name, email, or contact information) lets the app back up your progress to Firebase infrastructure operated by Google LLC, and lets you send an optional content report. Tanuki integrates no advertising SDK and does not sell your data or track you across other apps or websites. Optional Tanuki Pro purchases are processed entirely by the Apple App Store or Google Play, so we never see or store your payment details.

1. General Information

Tanuki ("the App") is a mobile application that teaches English speakers hiragana, katakana, kanji and the Japanese language, developed and published by IOCODO LLC ("we", "our", "us").

This Privacy Policy explains what information the App handles, how it is used, and the choices available to you. Tanuki is designed to be privacy-first: it is usable offline, and it never requires you to provide a name, email address, or any other personal detail.

2. Data Stored on Your Device

The App stores your learning data locally on your device, in a local database. This is the primary copy of your data and is what makes the App work offline. It includes:

Your learning progress and spaced-repetition review schedule (which kana, kanji, words and grammar points you have studied and when they are due for review)
In-app preferences and settings (sound, haptics, reminder time, and similar options)
Locally scheduled practice reminders, if you choose to enable notifications (these are scheduled on your device by the operating system and are not sent from any server)

This on-device data is removed when you uninstall the App, subject to any device backup behavior controlled by Apple or Google.

3. Account and Authentication

Tanuki does not require you to create an account or sign in to learn. To back up your learning progress and to let you submit a content report, the App signs you in anonymously using Firebase Authentication (Google LLC).

An anonymous sign-in generates a random identifier tied to your installation. No email address, name, password, phone number, or social login is collected. We have no way to identify you personally from this identifier.

4. Data Stored in Firebase Backend Services

Tanuki uses a small set of Firebase services operated by Google LLC:

Firebase Authentication: issues the anonymous identifier described above.
Cloud Firestore: stores a best-effort backup of your learning progress (your spaced-repetition review data), keyed to your anonymous identifier, so it is not lost if you reinstall the App on the same device. It also stores the content reports described in Section 5. No personal data is stored in either case.
Firebase App Check: verifies that requests come from a genuine Tanuki installation, using device attestation (App Attest on iOS, Play Integrity on Android). It does not collect personal information on our behalf.
Firebase Remote Config: lets us update small pieces of App configuration remotely, such as the minimum supported App version. It does not collect personal information.

The cloud backup is best-effort: if you are offline, or if background sync is unavailable for any reason, the App keeps working normally from the local copy on your device, which remains the source of truth.

5. Content Reports

If you tap "Something looks wrong?" to report a reading, translation, pitch-accent, or other content error, the App sends us a small report so we can fix it. A report contains only: the item being reported, the type of problem, a short note if you choose to add one, the App version, and your anonymous identifier. It contains no personal information and is used solely to improve the App's content. Reporting is always optional.

6. Analytics and Crash Reporting

Tanuki does not display advertisements and does not integrate any advertising SDK. There is no advertising identifier collection of any kind, and Tanuki does not track your activity across other apps or websites.

The App does use two Google-provided diagnostic services:

Firebase Analytics: records anonymous usage events (for example, which screen you opened or which level you completed) so we can understand how the App is used and improve it. These events never include your name, email, or any other personally identifying information.
Firebase Crashlytics: automatically collects crash and error reports if the App malfunctions, including your device model, operating system version, App version, and a technical log of what the App was doing at the time. This helps us find and fix bugs. Crash reports do not include your name, email, or the content of what you were studying.

7. Network Requests and Third-Party Services

During normal operation, the App communicates only with the following third-party services:

Firebase Authentication (Google LLC): anonymous identifier
Cloud Firestore (Google LLC): learning-progress backup and content reports
Firebase App Check (Google LLC): request integrity verification
Firebase Remote Config (Google LLC): remote App configuration
Firebase Analytics (Google LLC): anonymous usage analytics
Firebase Crashlytics (Google LLC): crash and error diagnostics
Google Fonts (Google LLC): font assets for this web page only

Important: Each third-party service listed above processes data under its own privacy policy. Please review those policies directly for provider-specific details on data handling and retention.

8. Payments and Subscriptions

Tanuki is free to start. An optional Tanuki Pro upgrade (a monthly or annual auto-renewing subscription, or a one-time lifetime purchase) unlocks the higher JLPT levels. All payments are processed entirely by the Apple App Store or Google Play. We do not operate our own payment system.

We never receive, see, or store your credit-card number, billing address, or any other payment details. The store reports back to the App only whether a valid Tanuki Pro entitlement exists, so the App can unlock paid content. That entitlement check contains no personal or financial information. Your purchases, billing, and refunds are governed by the privacy policy and terms of the store you bought from. See our Terms of Use for the subscription terms.

9. Data Sharing and Sale

We do not sell your data. We do not share your data with any third party except as required to operate the App (specifically, by transmitting your anonymous learning backup, content reports, and diagnostic data to the Firebase services described above) or as required by law. No data is shared with other users.

10. Account Deletion and Data Retention

You can delete your anonymous account and all associated data at any time:

In-app: open Settings, scroll to the bottom, and tap Delete account, then confirm. This clears all learning data stored on your device, removes your content reports, and deletes your anonymous Firebase Authentication identity.
By email: send a request to support@iocodo.com with the subject "Tanuki Account Deletion". We will complete the deletion within 30 days and confirm by reply.

After deletion, any remaining copy of your data in our backend systems, including the learning-progress backup described in Section 4, is removed within 30 days.

11. Children's Privacy

Tanuki is a general-audience education app. It is not directed at children under the age of 13, and we do not knowingly collect personal information from children. Because the App collects no personal information (name, email, or similar identifying details) from anyone, it is suitable for learners of all ages under the supervision appropriate to their context.

12. Your Rights (GDPR, CCPA and similar laws)

Depending on where you live, you may have rights over your data under laws such as the EU/UK General Data Protection Regulation or the California Consumer Privacy Act. Because Tanuki does not collect your name, email address, or other directly identifying information, most of these rights apply to the anonymous learning data described above. You can, at any time and without needing to prove your identity beyond having the App installed:

Access or export your learning data, by using the in-app export or review features where available, or by contacting us.
Delete your data and anonymous account, as described in Section 10.
Object to or restrict the anonymous backup and analytics described above, by using the App fully offline and declining optional features such as content reporting.
Contact us with any question or request about your data, at the email address in Section 14.

We do not sell personal information and there is no "sale" or "sharing" of data to opt out of under the CCPA.

13. Changes to This Policy

We may update this Privacy Policy from time to time. If we make material changes, we will update the "Last updated" date at the top of this page. Continued use of the App after changes are posted constitutes your acceptance of the updated policy.

14. Contact

If you have questions about this Privacy Policy, please contact:

IOCODO LLC
Email: support@iocodo.com
Website: iocodo.com