Privacy Policy
Last updated: 18 September 2026
Karyudo LLC ("we") handles information in the mobile application mixgo ("the app") as set out below.
1. Information we handle
| Information | How it is handled |
|---|---|
| Photographs and images | Processed entirely on your device. Text recognition runs locally; images are never sent to our servers or to any third party. |
| Recognised or pasted text | Sent, by way of our servers, to a language model provider in order to produce the mixed text (section 3). We do not store your text on our servers. The resulting text is kept on your device. |
| Learning records (words you know) | Stored on your device. Only if you sign in, a copy — the word, its frequency rank and how often you have confirmed it — is stored on our servers so it survives a change of device. |
| Usage records | To prevent abuse and to manage the free allowance, we record, per user, the number of sentences processed and the language-model usage. This does not include the content of your text. |
| Device integrity information | To prevent access from outside the app, we use the facilities provided by the operating system (App Attest / Play Integrity) and record a per-device key and the result of each check. |
| Account information | If you sign in with Apple or Google, we store the identifier they issue. Signing in is intended for paid users and is not required to use the app. |
| Purchase records | We store your subscription status and expiry date. We never receive your card number or other payment details. |
2. Purposes
- Providing the app's features (mixing text, reading it aloud, keeping your learning records)
- Carrying your learning records over to a new device or a reinstall
- Preventing abuse and excessive use, and keeping the service running
- Responding to your enquiries
We do not use your information for advertising, and we do not sell it to third parties.
3. Third parties and processors
The app relies on the following providers. Each handles information only to the extent needed for the purposes above.
| Provider | Purpose | Information sent |
|---|---|---|
| Google (Gemini API) | Aligning text word by word and producing the mixed text | The text being processed |
| Supabase | Server functions, database and sign-in | Those items in section 1 that are stored on our servers |
| RevenueCat | Managing subscription status | Purchase records and the user identifier |
| Apple / Google | Sign-in, in-app purchases, device integrity checks | As determined by each provider |
We do not disclose information to any other third party, except where required by law.
These providers operate servers outside Japan, principally in the United States, so information is stored and processed abroad. We rely on our contracts with each provider, and on the safeguards each provider publishes, to ensure it is handled properly.
4. Retention
Information held on our servers is kept for as long as your account exists, or for as long as it is needed to manage usage. If you delete your account, the information held on our servers for that account is deleted. Information on your device is lost when you delete the app.
5. Deleting your account
You can delete your account from the app's settings screen. Doing so erases your learning records, usage records and sign-in information from our servers. Fees already paid are not refunded. To cancel a subscription, use the settings in the App Store or Google Play.
6. Children
The app is not directed at any particular age group, and we do not knowingly collect information from children.
7. Changes to this policy
If we change this policy, the revised version will be published on this page. Significant changes will also be announced within the app.
8. Contact
For questions about this policy, please write to support@karyudo.co.jp.
Karyudo LLC