Privacy policy

1. Who we are

Tanuki is made by IOCODO LLC, a limited liability company registered in Wyoming, United States. We decide why and how the data described on this page is used, so under European data protection law we are its controller.

Postal address: 30 N Gould St Ste N, Sheridan, WY 82801-6317, United States
Email: support@iocodo.com

Use this email for anything about your data, including the requests described in Your rights.

2. What this policy covers

This policy covers the Tanuki app on iOS and Android, and the Tanuki pages on iocodo.com, this one included. Tanuki is an app for learning Japanese from hiragana and katakana up, with lessons, spaced review, kanji, grammar and graded reading.

Here, "personal data" means any information about you as a person who can be identified, directly or indirectly. That includes identifiers such as a user ID, an installation ID or a device token, even when they do not contain your name.

3. Data that stays on your device

Tanuki keeps the following on your device, in the app's own storage:

• your learning progress and review schedule, which the app also backs up (see Accounts and sign-in)
• your daily practice record and your reading progress
• your settings, such as the language the app explains in, sound, daily goal and reminder time
• your daily reminders, which your phone's operating system holds
• the word audio you download for your level
• your privacy choices, each with its date, the version of the text you saw, the app version, the region the app worked out for you and, where the app asked for your consent, the age its Allow button stated (see Your choices in the app)
• the country of your App Store or Google Play account, as the store last reported it, so the app starts in the right mode (see Russia and China)
• whether you have Tanuki Pro, as the store or our database last confirmed it, so the paid levels open offline

We do not receive any of this, unless another section of this policy says otherwise. If you back up your device with iCloud or Google, the backup can include a copy of this data, under Apple's or Google's terms. On Android, restoring that backup does not bring back your sign-in: the app starts with a new guest account, and if you had signed in, you sign in again. Uninstalling the app deletes this data from your device.

4. Accounts and sign-in

Tanuki uses Firebase Authentication, a Google service, to recognize your account.

This section does not apply when the country of your App Store or Google Play account is Russia or China: see Russia and China.

The first time the app opens with an internet connection, Firebase Authentication gives your installation a guest account with a random user ID. It does not contain your name or email address, but it is a pseudonymous identifier: it links the data the app keeps on our servers to your installation.

The app uses this account to back up your progress automatically. For each kana, kanji, word and grammar card you have studied, the backup holds:

• when you last reviewed it and when it is next due
• how often you have reviewed and forgotten it
• how well the review scheduler estimates you know it
• the memory hook you wrote for it, if you wrote one

Signing in is optional, from Settings. Your progress carries over to the signed-in account, so you can use it on another device or after reinstalling the app.

If you sign in with Google, we receive from Google your email address, the name and profile picture of your Google account and a Google user ID, and Firebase Authentication stores them to keep you signed in.

If you sign in with Apple, we receive an Apple user ID and, the first time only, the name and email address you choose to share. If you choose to hide your email address, Apple gives us a private address that forwards to yours.

Tanuki shows your name or email address only to you, in Settings. Settings, then Sign out starts a new guest session on this device, and your signed-in account is not deleted.

5. What we use data for, and on what legal basis

European data protection law (the GDPR and the UK GDPR) requires a legal basis for each use of personal data. For each use, here is the data involved and the basis we rely on.

• Running the app: your account, the backup of your progress, the word audio, keeping the app configured and confirming that requests come from the genuine app

  Data: your user ID, the progress backup, installation identifiers and App Check tokens, the IP address your phone uses to download audio and, if you sign in, what Apple or Google share with us.

  Legal basis: Performance of our contract with you, that is, providing the app you asked for (GDPR art. 6(1)(b)).

• Selling and unlocking Tanuki Pro

  Data: the plan you buy and the store's confirmation of the purchase, which the app checks on your device; if we give you Tanuki Pro as a gift, a record of the gift kept with your user ID.

  Legal basis: Performance of our contract with you, that is, providing the app you asked for (GDPR art. 6(1)(b)).

• Handling the reports, language requests and emails you choose to send

  Data: what you send (see Reports and emails you send us), with your user ID for reports and your email address for emails.

  Legal basis: Performance of our contract with you, that is, providing the app you asked for (GDPR art. 6(1)(b)).

• Knowing which versions of the app are in use and who has Tanuki Pro, so we can fix or retire a faulty version and help paying learners

  Data: a device record kept with your user ID:

  • the last day and time you opened the app
  • the app version and build, and whether the device runs iOS or Android, with which system version
  • whether you have Tanuki Pro, of which kind (monthly, annual, lifetime or gift), and since or until when

  Legal basis: Our legitimate interests (GDPR art. 6(1)(f)): keeping the app working for everyone who uses it and supporting the people who pay for it. You can object at any time by writing to us.

• Counting how the app is used and fixing crashes

  Data: usage events, labels that describe your installation, crash and error reports, device model, system version, app-instance and installation identifiers, and a coarse location that Google derives from your connection (details in Who receives data).

  Legal basis: It depends on where you are.

  • Your consent (GDPR art. 6(1)(a) where the GDPR applies) in these places, where usage statistics and crash reports stay off until you allow them:
    • in the European Union, Norway, Liechtenstein, Vietnam and Brazil, the app asks you once, in a window with both switches off. Its Allow button states the age from which you can decide this yourself where you live (18 in Brazil). In Vietnam, the window also says that usage statistics count as sensitive personal data there and that under 16 a parent or guardian decides.
    • in Canada and, from build 38 of the app (the number in brackets after the version, in the app's menu), in Türkiye and the United Kingdom, no window asks: you turn each one on in Privacy choices.
  • Our legitimate interests (GDPR art. 6(1)(f)) everywhere else: understanding how the course is used and fixing what breaks. On iPhone, and in Switzerland on both systems, they start when you tap OK on a short notice that the app shows once; until then they stay off. On Android, they start when you first open the app.

  The app does not send them from simulators and test devices. Wherever you are, you can object by writing to us, and on iPhone and in the places listed above you can also switch each of them on or off in Settings, then Privacy choices.

• Sending the News from Tanuki notifications

  Data: a registration token that Firebase Cloud Messaging creates on your phone, and the notification topics the app subscribes your phone to (see Notifications).

  Legal basis: Your consent (GDPR art. 6(1)(a) where the GDPR applies). News from Tanuki is off until you turn it on in Settings, and until then the app has no registration token. You can turn it off again at any time.

• Showing the Tanuki pages on iocodo.com

  Data: your IP address, your browser and device type, the page you open and the page that sent you there, in the server logs of our hosting provider.

  Legal basis: Our legitimate interests (GDPR art. 6(1)(f)): running our website. You can object at any time by writing to us.

6. Who receives data

We use these service providers to run Tanuki. Each one receives only the data listed, for the purpose listed:

• Firebase Authentication (Google LLC)

  What for: creates and recognizes your guest or signed-in account.

  Data: your user ID and, if you sign in, the email address, name, profile picture and user ID that Apple or Google share. Firebase also logs the IP addresses of sign-in requests. Firebase Authentication runs only in the United States.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase Authentication privacy information

• Cloud Firestore (Google LLC)

  What for: our database.

  Data: with your user ID, the progress backup, the device record, your reports and any Tanuki Pro gift. Cloud Firestore keeps this data in the European Union.

  Google LLC processes this data on our behalf, under its data processing terms. Cloud Firestore privacy information

• Firebase Hosting (Google LLC)

  What for: serves the word audio the app downloads, and the Tanuki pages on iocodo.com.

  Data: standard server logs, which include your IP address and the file or page requested.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase Hosting privacy information

• Google Analytics for Firebase (Google LLC)

  What for: counts how the app is used, while usage statistics are on (see What we use data for).

  Data:

  • usage events, such as the screens you open, the lessons you start and finish, how you answer exercises (which item, right or wrong, and how fast), the Tanuki Pro screen, and your purchases with their price, currency and store transaction number
  • labels that describe your installation, such as your level, the language the app explains in, whether you have Tanuki Pro, whether reminders are on, whether you signed in with Apple or Google, and the app build
  • an app-instance identifier, device model, system version and a coarse location that Google derives from your connection

  Google LLC processes this data under the Google Analytics terms. Google Analytics for Firebase privacy information

• Firebase Crashlytics (Google LLC)

  What for: reports crashes and errors so we can fix them, while crash reports are on.

  Data: crash and error reports (what the app was doing, device model, system and app version, memory and disk state) with installation identifiers.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase Crashlytics privacy information

• Firebase Remote Config and Firebase Installations (Google LLC)

  What for: keep the app configured, for example switching a feature off remotely or asking you to update.

  Data: an installation identifier.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase Remote Config and Firebase Installations privacy information

• Firebase App Check (Google LLC)

  What for: confirms that requests come from the genuine app.

  Data: an attestation from Apple's App Attest or Google Play Integrity and a short-lived App Check token.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase App Check privacy information

• Firebase Cloud Messaging (Google LLC)

  What for: delivers the News from Tanuki notifications, if you turn them on (see Notifications).

  Data: an installation identifier, a registration token and the topics your phone is subscribed to. We do not keep the token in our database.

  Google LLC processes this data on our behalf, under its data processing terms. Firebase Cloud Messaging privacy information

• IT service providers (United States)

  What for: tools we may use to read reports and emails and to draft our replies.

  Data: the text of a report, with the first characters of its user ID, or of an email, when we use these tools for it.

  These providers handle this data under their own terms.

• GoDaddy Professional Email (GoDaddy)

  What for: hosts our support mailbox, support@iocodo.com.

  Data: the emails you send us and our replies.

  GoDaddy stores this data for us. GoDaddy privacy policy

Apple (App Store) and Google (Google Play) also handle your download and any purchase, under their own privacy policies. If you sign in with Apple or Google, they share with us the data described in Accounts and sign-in.

We do not sell your personal data, and we do not use it for targeted advertising.

7. Notifications

Tanuki uses notifications in two ways, and both stay off until you turn them on:

• Practice reminder. Your phone schedules it, at the time you choose in Settings.
• News from Tanuki. Now and then, a notification about new lessons or features, or a reminder that your reviews are waiting. You turn it on or off in Settings, then News from Tanuki. It is not offered where your phone points to Korea, nor in the phone-only mode described in Russia and China.

When you turn News from Tanuki on, the app registers your phone with Firebase Cloud Messaging, a Google service, and subscribes it to topics:

• everyone who uses Tanuki, and everyone on the same system (iOS or Android)
• the language the app explains in
• the week, and the day, when you last opened the app, so that a message can reach the people who have not opened it for a while; each of these groups is split in two halves, worked out from your user ID, so we can see whether a message made a difference

On iPhone, the app does this only once Tanuki's notifications are allowed on your phone, and turning the switch on asks you for that. The topics hold no name or contact detail, we never learn who is in a topic, and we do not keep the registration token in our database.

Until you turn it on, the app does not register your phone and has no registration token. When you turn it off or delete your account, the app unsubscribes your phone from every topic and deletes the token.

Versions before 1.0.12 registered phones without asking: every Android phone when the app started, and an iPhone once Tanuki's notifications were allowed on it. If yours was registered that way, the app removed the registration and deleted the token when it updated, and News from Tanuki stays off until you turn it on.

Nothing appears on your screen unless Tanuki's notifications are allowed in your phone's settings.

8. Reports and emails you send us

When you tap Something looks wrong? and send a report, or ask for another language for the explanations, the app sends us:

• the item and the type of problem, or the language you ask for
• the text that was on screen
• the detail you add, if you add one (up to 200 characters)
• the language the app explains in, the app version and the date
• your user ID, so the report is deleted with your account

Please do not write personal details in the detail field.

If you email us, from the app or directly, we receive your email address, the name your email shows and what you write. The email the app prepares for you adds the app version, the platform and the system version, and you can read and change the draft before you send it.

We read reports and emails to fix the course and to answer you.

9. The Tanuki pages on iocodo.com

The Tanuki pages on iocodo.com are served by Firebase Hosting (Google LLC), which keeps standard server logs, including your IP address. They load no analytics or advertising scripts.

The landing page remembers in your browser which language version you used, so it opens in that language next time. That choice stays in your browser.

The App Store and Google Play buttons tell the store which of our pages or campaigns sent you there. If you opened a link that someone shared from the app, the Google Play button also passes on the short invite code in that link. The code is worked out from the user ID of the person who shared it and does not reveal that ID.

10. Where data is processed

IOCODO LLC is registered in the United States. Our service providers may process your personal data:

• in the European Union: Tanuki's database (Cloud Firestore)
• in the United States only: accounts (Firebase Authentication)
• in the United States and in other countries where their providers run servers: the other services in this policy

Where European, UK or Swiss data protection law requires a safeguard for this, we rely on:

• the EU-U.S. Data Privacy Framework, its UK Extension and the Swiss-U.S. Data Privacy Framework, for providers certified under them (you can check a provider on dataprivacyframework.gov)
• the Standard Contractual Clauses approved by the European Commission, with the UK Addendum and the Swiss adjustments, which are part of our providers' data processing terms

You can ask us for a copy of these safeguards at support@iocodo.com.

11. How long we keep data

Here is how long we keep each kind of personal data. Items marked automatic are deleted on a fixed schedule, without anyone having to ask.

• Your account and what our database keeps with it

  Until you delete your account, in the app or by email. This covers the progress backup, the device record, your reports and any Tanuki Pro gift record.

• Guest accounts that hold no progress and no purchase

  Deleted in our periodic clean-up once they have not been used for 90 days.

• Usage events in Google Analytics

  14 months. automatic

• Crash and error reports

  90 days. automatic

• IP addresses that Firebase Authentication logs

  A few weeks. automatic

• Installation identifiers

  Firebase keeps them until we ask it to delete them, and then removes them within 180 days. Deleting your account in the app does not ask for this.

• Reports and emails we handle with our IT service providers

  Until we delete them there; the providers keep them under their own terms.

• Emails you send us

  We keep the emails you send to support and our replies as a record of our support, so we can help you if you write again and show how we handled your request. We delete them when you ask us to.

• Server logs of the word audio and of the Tanuki pages

  As long as Google keeps them under its own rules. Until October 13, 2026, Cloudflare Web Analytics also counted visits to the Tanuki landing pages, and Cloudflare keeps the counts it made until then under its own rules.

• What the app keeps on your phone

  Until you uninstall the app. Delete account also erases your learning data on the device.

When you delete your account or ask us to delete your data, we delete it as described here, unless the law requires us to keep part of it.

12. How we protect data

Data travels between the app and our service providers over encrypted connections (HTTPS).

Our providers encrypt the data they store for us, and the access rules of our database limit what each user can read and change. Access to our systems is limited to the people who run Tanuki, and only to run and support it.

If a security incident puts your personal data at risk, we tell you and the competent authorities when the law requires it.

13. Your choices in the app

Settings, then Privacy choices has one switch for each of these uses of your data. A change applies right away, and the app works the same with both of them off.

• Usage statistics, counted by Google Analytics for Firebase
• Crash reports, sent to Firebase Crashlytics

Privacy choices is there on every iPhone, and on Android wherever these switches start off or wait for the notice (the places are listed in What we use data for). On Android elsewhere, the app has no switch for them, and you can object to them by writing to us.

The app works out which of these rules applies on your phone from the regions of the languages set on it, its time zone and the country of your App Store or Google Play account. If any of them points to one of the places listed, the app treats you as being there, and it keeps that stricter rule even if you later travel or change these settings.

You can also:

• turn News from Tanuki on or off in Settings (see Notifications)
• turn the practice reminder on or off, and choose its time, in Settings
• use Tanuki as a guest, or sign in with Apple or Google; Settings, then Sign out starts a new guest session on the device
• send a report or an email only when you choose to
• delete your account with Settings, then Delete account (see Deleting your data)
• allow or block Tanuki's notifications in your phone's settings

Wherever you are, you can object to any use of your data by writing to us, as described in Your rights.

14. Your rights

Wherever you live, you can ask us to:

• tell you what personal data we have about you, and give you a copy
• send that copy to you, or to another company, in a machine-readable format
• correct data that is wrong or incomplete
• delete your data
• stop or limit a use of your data, including any use based on our legitimate interests

To ask, write to support@iocodo.com. It is free. We reply within one month, and we may ask you to confirm that the data is yours before we act.

You can also withdraw any consent you gave, at any time: in the app, with the switches in Privacy choices and with News from Tanuki, or by writing to us. This does not affect what we did with your data before you withdrew it.

Deleting your data

You can delete your account and its data:

• in the app: Settings, then Delete account, at the bottom of the page. This deletes:
  • your account, guest or signed in
  • what our database keeps with it: the progress backup, the device record, your reports and any Tanuki Pro gift record
  • your phone's registration for News from Tanuki, if you had turned it on
  • your learning data and settings on the device
  The app then starts again with a new, empty guest account.
• by email: write to support@iocodo.com with the subject "Tanuki Account Deletion", and if you signed in with Apple or Google, tell us the email address of that account. We delete your account and its data within 30 days and confirm by reply.

We cannot find a guest account from an email address. If you use Tanuki as a guest, delete it in the app. In the phone-only mode for Russia and China there is no account in the app to delete: see Russia and China.

Deleting your account does not delete usage statistics, crash reports or installation identifiers, which Tanuki does not store with your account. They are deleted as described in How long we keep data. Data that stays on your device is deleted when you uninstall the app.

Complaints

You also have the right to complain to an authority:

• in the European Union and the European Economic Area, the data protection authority of the country where you live or work (list of authorities); in Italy, the Garante per la protezione dei dati personali
• in the United Kingdom, the Information Commissioner's Office
• in Switzerland, the Federal Data Protection and Information Commissioner
• in Brazil, the Agência Nacional de Proteção de Dados
• in the United States, the attorney general of your state

If you are in Brazil, you have the rights listed in article 18 of the LGPD (Lei 13.709/2018), and you can use them as described above. If you ask us for your data, we send a complete answer within 15 days, not one month.

15. Privacy rights in US states

Several US states, including California, Colorado, Connecticut, Delaware, Oregon, Texas and Virginia, give their residents privacy rights. We give the same rights to everyone in the United States:

• to know what personal information we collect, use and disclose, and to get a copy of it
• to correct it
• to delete it
• to opt out of the sale of your personal information, of its use for targeted advertising and of profiling that has legal or similarly significant effects
• to appeal if we turn down your request
• not to be treated differently for using any of these rights

The personal information we collect, where it comes from, why we use it and who receives it are described in What we use data for and Who receives data. We collect no sensitive personal information.

We do not sell your personal information, and we do not use it for targeted advertising or for profiling with legal or similarly significant effects.

To use these rights, write to support@iocodo.com, or have someone you authorize write for you. For a guest account, you can also delete your data in the app (Deleting your data). You do not need an account to make a request. We reply within 45 days. If we turn your request down, you can appeal by replying with the word "Appeal" in the subject. We answer an appeal in writing within 45 days, and if you still disagree you can contact the attorney general of your state.

16. Notices for some countries

Brazil

For parents, guardians, children and adolescents in Brazil: the risks we assessed for young users and how Tanuki protects them, in Portuguese (Lei 15.211/2025, art. 16).

Canada

The service providers listed in Who receives data collect and keep data for us. They may process it outside Canada, in the European Union, the United States and other countries where they run servers. The courts and authorities of those countries can have access to it under their laws.

Japan

What the app sends from your device to other companies, who receives it and why is set out in Japanese on 外部送信について. From build 38, on a phone whose language settings, time zone or app store point to Japan, the Today screen ends with a link to that notice, 利用者情報の外部送信について.

Korea

This policy in Korean, with the processing we entrust to other companies and the processing abroad, is on 개인정보 처리방침.

Mexico

Our privacy notice for people who use Tanuki in Mexico is in Spanish on Aviso de privacidad. It lists the data we use, what is needed to run the app and what is not, and how to use your rights of access, rectification, cancellation and objection.

Russia and China

From version 1.0.12, when the country of your App Store or Google Play account is Russia or China, Tanuki keeps your progress on your phone only. There, the app:

• runs without sign-in, does not create an account for you and does not back up your progress to our servers
• runs without the Google Firebase services listed in Who receives data, apart from the audio download in Russia described below, so what this policy says about accounts, the backup, the device record, usage statistics, crash reports and News from Tanuki does not apply
• shows no privacy window and no Privacy choices

In Russia, the app still downloads the word audio for your level from Firebase Hosting, whose server logs include your IP address. In China, it downloads no audio and plays only the audio it comes with.

The app asks the store on your phone for that country each time it starts. Until the store has answered for the first time, the app goes by your phone's time zone.

Tanuki Pro then comes from the store alone, and you restore a purchase through the store. A report or a request for another language opens a draft in your own email app, which you read and send yourself. Settings, then Reset course erases your progress on the phone, and so does uninstalling the app: we cannot bring it back.

Our servers may hold a copy of your progress from before: from an earlier version, or from a start at which the store had not answered yet. In Russia, at a start at which the store itself answers Russia, the app looks on your phone for the account that copy is kept under. If it finds one, it connects to Google Firebase for this one task and deletes that account and what our database keeps with it, and then tells you once that the copy was deleted. Your progress on the phone is not touched, and if the phone is offline the app tries again the next time it starts.

There are two limits. If you had signed in with Apple or Google and our servers ask for a fresh sign-in before they delete an account, the app deletes the copy and signs you out on the phone, and the account itself stays, with the email address it carries. We look for these accounts each time we clean up our servers and delete the ones we find. An account that is no longer on the phone, for example one you had signed out of, is out of the app's reach. In China, the app does not delete an earlier copy. In each of these cases you can have it deleted as described in Deleting your data.

Türkiye

Our notice for people who use Tanuki in Türkiye, with the purposes, the legal bases, who receives the data and your rights under Law No. 6698, is in Turkish on Aydınlatma metni. It is a separate text from any consent you give in the app. From build 38, on a phone whose language settings, time zone or app store point to Türkiye, usage statistics and crash reports start off, and each has its own switch in Privacy choices, with a line in Turkish that says what it is for and who receives the data.

Vietnam

If you use Tanuki in Vietnam, your personal data is transferred abroad. Which data, who receives it and for what purposes, and how to use your rights, is set out in Vietnamese on Thông báo về dữ liệu cá nhân.

17. Children

Tanuki is not meant for children under 13. The app itself does not ask your age.

From build 38, where a law asks us to (in some US states, for example), the app asks your app store for your age range each time it starts. On iPhone, Apple may ask you or a parent whether to share it; on Android, the app never shows Google Play's request. The app uses the range only for what those laws require and keeps it only in memory while it runs: it does not save it on your phone, send it to us or put it in usage statistics or crash reports. If the store reports that you are under 13, the app does not offer News from Tanuki and removes the phone's registration for it until the next start, when it asks the store again.

If we learn that a child under 13 has given us personal data, we delete it. If you think this has happened, write to support@iocodo.com.

18. "Do Not Track" and other companies

Some browsers and devices can send a "Do Not Track" signal. There is no common standard for responding to it, so Tanuki and its pages on iocodo.com do not change what they do when they receive one. The choices described in this policy are how you control your data.

Apart from the service providers listed in Who receives data and The Tanuki pages on iocodo.com, we do not let other companies collect personal data about your activity over time and across other apps and websites through Tanuki.

19. Changes to this policy

We update this policy when Tanuki or the law changes, and the date at the top shows when the current version took effect. If a change affects how we use data you have already given us, we tell you in the app before it applies, and we ask for your consent where the law requires it.

This version was last updated on October 15, 2026. To receive an earlier version, write to us.

20. Contact

IOCODO LLC
Postal address: 30 N Gould St Ste N, Sheridan, WY 82801-6317, United States
Email: support@iocodo.com