Katakoi Studio Privacy Policy ID EN

Privacy Policy

Katakoi Kanji Effective 13 September 2026 Updated 13 September 2026

Katakoi Kanji is a Japanese vocabulary learning app built by Katakoi Studio. This page explains what data we collect, what it is used for, and what rights you have over it. By using Katakoi Kanji, you agree to the practices described here.

What we collect

Account data

When you sign up, we collect:

If you choose Continue with Google, we never receive your password. What we receive from your Google account is your email address, your name, and your profile picture.

Profile data

You can set a display name and upload a profile picture. Both are optional. Profile pictures are stored in Supabase Storage.

Learning data

As you use the app, we store the level you selected, your vocabulary progress and which cards you have studied, when each card is next due for review, your study calendar history, and your app settings including interface and content language preferences.

Premium access data

Katakoi Kanji does not use recurring subscriptions. Premium access is bought once and lasts 30 days; it does not renew automatically. Buying again before it runs out adds to the days you have left. All we store is whether your premium access is active, and when it expires.

Important

We never receive, process, or store credit card numbers, bank details, or any other payment instrument. All transactions are handled by Google Play.

Developer report data

If you use the Report to developer feature, we store the message you send, your email address, the app version, your device OS version, and the time it was sent. This is only collected if you use the feature.

What we do not collect

The app shows no advertising and shares no data with any ad network.

How your data is used

The data we collect is used only to:

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

Where data is stored

On our servers

Account data, profile pictures, and learning data are stored with Supabase, the database and authentication provider we use. Access is restricted per user: you can only read and write data belonging to your own account.

On your device

The app keeps a small set of vocabulary cards in local device storage so it keeps working while you are offline. This local data is removed automatically when you uninstall the app.

How long we keep it

Your data is kept for as long as your account is active. If you request account deletion, it is removed as described in section 5.

Third parties

We rely on the following services to run the app:

Supabase
Database and authentication.
Receives: email address, encrypted password, profile picture, learning progress.
Google Sign-In
Authentication, if you choose to sign in with your Google account.
Gives us: your email address, name, and profile picture from your Google account.
Google Play
App distribution and premium access payments.
Receives: transaction data, handled entirely by Google.

We share your data with no one outside this list, unless required to by applicable law.

Your rights

You have the right to access the data we hold about you, correct anything inaccurate, and request deletion of your account along with all learning data attached to it.

How to request account deletion

There is no delete-account button inside the app. Deletion is handled manually by our team. Email katakoi.dev@gmail.com from your registered address and tell us you want your account deleted.

What gets deleted:

  • Your account — email address and password
  • Your profile — display name and profile picture
  • All learning data — vocabulary progress, review schedule, study calendar history, and app settings

Requests are processed within a reasonable time of being received. Data we are legally required to retain may be kept longer, in a form no longer linked to your identity.

Deleting your account does not refund premium access you have already bought, and any remaining days end with it.

Security

All traffic between the app and our servers is encrypted over HTTPS. Passwords are stored in encrypted form and cannot be read by anyone, including us.

That said, no system is completely immune. We encourage you to use a unique password that you do not reuse elsewhere.

Children

Katakoi Kanji is not directed at children under 13, and we do not knowingly collect data from them. If you are a parent or guardian and believe your child has created an account, contact us and we will delete the data.

Changes to this policy

We may update this policy as the app gains features. If a change materially affects how we handle your data, we will tell you through the app or by email before it takes effect. The date of the most recent update is always shown at the top of this page.

Contact

Questions or complaints about this policy can be sent to:

Katakoi Studio
katakoi.dev@gmail.com
Bandung, Indonesia