Privacy Policy

1. Information handled by the App

The App stores the following information locally on the user’s device:

• Learning history
• Review state
• Favorites

This information is used within the App to provide learning progress, review scheduling, and favorites. Yuiver does not collect or sync it to a Yuiver server.

The App currently does not use:

• Registration, Yuiver accounts, or cross-device sync through a Yuiver server
• Advertising or behavioral analytics SDKs
• Remote error collection, remote crash reporting, or automatic log uploads

2. File backup, import, and operating-system backup

• Manual file backup and import: The system file picker is used to save or import a backup file only when the user starts the action in the App. The App does not automatically upload backup files to a Yuiver server.
• Operating-system account backup: Depending on the device, operating system, and the user’s backup settings, local App data may be included in and restored from a device or account backup provided by Google or Apple. This is not a Yuiver account or Yuiver sync service.

If the user saves a backup file to cloud storage or a shared location, the selected storage provider’s privacy policy and settings apply.

3. Bundled study audio and production-stage speech synthesis

The App includes prerecorded audio for Japanese expressions and examples and plays those files offline at runtime. The App does not call Google Cloud Text-to-Speech while it is running, and a Japanese system voice does not need to be installed on the user’s device.

Yuiver uses Google Cloud Text-to-Speech when developers prepare study-content audio before distribution. The source text used for synthesis is the learning content distributed with the App. Text entered by users and users’ learning records are not sent to Google Cloud or a Yuiver server for speech synthesis.

4. In-App feedback and email support

The App’s feedback button opens a compose screen in an external email application only when the user selects it. Information such as the App version and identifiers for the relevant content or course may be prefilled in the subject or body. The user can review, edit, or remove that information before sending. Email is not sent automatically, and no logs or files are attached automatically.

If a user sends an email to [email protected] or [email protected], the following information may be processed:

• The sender’s email address and name displayed by the email service
• The inquiry or feedback content the user sends
• Files the user chooses to attach

This information is used to review and respond to the message, investigate the issue, and provide follow-up support. Do not include passwords, full payment card numbers, identification documents, or other sensitive information in an email.

5. Website access information, cookies, and analytics

The website has no registration or contact form and uses no first-party cookies, advertising, behavioral tracking, or visitor analytics tools.

Cloudflare may process technical information such as an IP address, browser information, and request time to deliver and protect the static website. Yuiver does not use this information for advertising or behavioral analytics.

6. Purposes of processing

• Providing learning progress, review, and favorites locally on the device
• Saving and importing backup files when requested by the user
• Reviewing and responding to inquiries and feedback, investigating issues, and providing follow-up support
• Providing the website, preventing malicious requests, and maintaining reliability
• Meeting legal obligations and handling disputes

7. Roles of external services and third-party disclosure

Yuiver does not sell personal information. Yuiver does not receive the App’s local learning data on a Yuiver server or provide it to third parties for advertising or analytics. The following services have roles in user choices, device settings, website and email operations, or the preparation of distributed content:

• Cloudflare: Website delivery, transport security, and malicious traffic prevention
• Google Workspace: Receipt, delivery, and storage of Yuiver support and contact email
• Google or Apple platform services: App data backup and restore according to device settings
• Google Cloud Text-to-Speech: Used by developers to prepare distributed study-content audio in advance. It is not called while the App is running, and users’ learning records or inputs are not sent to it for speech synthesis.
• The user’s selected email or storage provider: Email delivery or storage of a manual backup file

Cloudflare, Google Workspace, platform services, and providers selected by the user process information as needed to provide their services under their own privacy policies and the user’s settings. Google Cloud Text-to-Speech is used only for the developer-side production process described above.

8. Retention and deletion

• Local App data: It may remain on the device until the user removes the App or uses the operating system’s data-management controls. Copies included in an operating-system backup may remain or be restored separately under the retention rules and backup settings of the user’s Google or Apple account.
• Manual backup files: They remain in the location selected by the user and must be deleted by the user from that location.
• Support and contact email: It is retained until the inquiry is resolved and follow-up support is no longer needed, then deleted without undue delay. If retention is required by law or needed to handle a dispute, it is retained only for the necessary scope and period and then deleted.
• Website access information: Cloudflare’s retention rules for service delivery and security may apply.

To request deletion of support email retained by Yuiver, contact [email protected].

9. User rights and choices

A user may request access to, correction or deletion of, or restriction of processing of their email inquiry information retained by Yuiver. Requests will be handled under applicable law after the requester is verified.

Yuiver cannot remotely access learning history stored on a device or backup files retained by the user. This information must be managed through the controls of the device, operating system account, or storage provider selected by the user.

10. Safeguards

Yuiver uses no automatic server transmission of App data and applies safeguards appropriate to the service, including restricted email access, HTTPS for the website, security response headers, and data minimization.

11. Contact

Privacy inquiries and deletion requests: [email protected]

12. Changes and revision history

This page will be updated before the way personal information is handled changes. Material changes may also be announced separately through the App or website when appropriate.

• September 26, 2026: Replaced the runtime system-TTS description with bundled offline study audio and documented the developer-side production role of Google Cloud Text-to-Speech.
• August 5, 2026: Added Yuiver Japanese to the scope and documented local data, backup, system TTS, in-App feedback, and support-email practices.
• August 3, 2026: Initial website Privacy Policy took effect.