English Navi Hub Privacy Policy

1. About this policy

This policy explains the learning features and data practices of English Navi Hub. This version requires no app account and contains no advertising, advertising SDK, or app-specific analytics or crash-reporting SDK. Developer Debug/QA builds have a different configuration. The app is intended for users aged 13 and over. It does not request an age entry or an account for age verification.

2. Learning data and preferences on your device

The app stores learning material, quiz attempts, correctness, answer times, referenced senses and material versions, learning directions, choice counts, review progress, due dates and progress events in a database on your device. Statistics come from actual answers; simply viewing cards or playing speech does not increase correct-answer counts. Four preferences—learning direction, choice count, theme and pronunciation locale—are retained locally. The app has no feature that automatically sends these records to the operator's server.

3. JSON backup and restore

When you start a backup in Settings, the app exports quiz history, review progress and events, the four preferences and compatibility information to a UTF-8 JSON file. You choose the destination in Android's file picker. Material masters, diagnostic logs and credentials are excluded. The app does not encrypt the backup JSON. Please manage access to the destination and any external copies carefully.

Restore replaces the relevant learning data and four preferences after file validation and your confirmation. Incompatible material references and invalid files are rejected. Recovery data is held inside the app while restoring and removed after restore or recovery completes. It may remain after an error, and recovery may be attempted on restart. This feature is not automatic cloud synchronization.

4. Retention and deletion of learning data and logs

After confirmation, “Delete learning data” removes quiz history, review progress and progress events. It does not delete material, the four preferences, diagnostic logs or externally saved JSON files.

The app records predefined event names, such as app startup and successful log-file creation, with UTC timestamps in a local diagnostic log. It does not accept arbitrary input or material text as diagnostic log content. Before appending an event, it clears an existing file that exceeds 64 KiB. This does not guarantee that the file always remains below that size and is not deletion after a set number of days.

“Delete logs” removes only the original diagnostic log inside the app. It does not remove learning records, preferences, share-cache copies or external copies. Android may remove share-cache files, but their deletion time is not guaranteed. No automatic expiry period is set for learning history or preferences. Android's app-data controls can also manage remaining local data. Android automatic backup is disabled, but this does not guarantee identical migration or reinstallation behavior across operating systems and device manufacturers.

5. Sharing diagnostic logs and external destinations

“Export logs (share)” creates a TXT copy of the diagnostic log in the app's private cache and opens Android's standard share sheet. Temporary read permission for the file is granted to the selected receiving app. The app does not automatically choose a recipient or send a message, and closing the share sheet does not establish that sending succeeded. Canceling sharing leaves the original diagnostic log intact.

Your selected sharing app or file destination may be an email or cloud service. Its communication, storage and deletion practices also depend on that provider's settings and policies. In-app deletion cannot remove copies already sent or saved elsewhere.

6. Text to speech

Playback uses the device's default Android TextToSpeech engine, to which the app passes the text to be spoken. The app requests a locale, such as US or UK English, and indicates a fallback or unavailable speech when necessary. Network requirements, external processing and retention depend on the chosen engine, voice and settings. The app does not enforce offline-only voices and cannot guarantee that every engine avoids external transmission. Please review your device's speech settings and the provider's information. Speech playback alone does not change learning scores or review progress.

7. Contact and website

For inquiries, please use the Sekimo Games contact form.

Please use https://sekimogames.com/en/contact/ and enter “English Navi Hub” in the app field. Names, reply email addresses, message text and other information you enter in the form are handled to respond to inquiries. The app does not automatically attach learning history or logs to the form. Please do not send passwords or private keys.

For the form, communications and access information handled after visiting the website, also see https://sekimogames.com/en/privacy/ . You may use the contact form to ask about handling or deletion of inquiry information. The operator cannot remotely delete data on your device or copies in external destinations.

8. Advertising and changes

This release is ad-free and contains no AdMob or UMP SDK or Advertising ID permission. If advertising, accounts, external synchronization, analytics or other processing is added, the implementation, third-party practices, required consent, store disclosures and this policy will be reviewed. Updates will be announced on this page.