Introduction
Sapilumen is an application and knowledge base for structured language learning. This policy explains what data is processed when you use the application and website, and how you can control it. We aim to collect as little as possible and to describe our data practices clearly.
Data we collect
The data practices in this section concern the Android application. Website analytics is described in the separate section below.
Android system backup and device transfer, where supported, are described below.
- No account. Registration is not required. You can study without a login, email address or password.
- Progress is stored locally. Your learning progress, practice results and settings are saved on your device. Sapilumen does not send them to its own servers for storage or synchronisation.
- No Firebase or third-party data collection SDKs. The app does not use these services or SDKs.
- No advertising. The application contains no advertising networks or advertising identifiers.
- No analytics in the Android app. The app does not send behaviour or usage data to analytics services.
Website analytics
Website supplement: September 8, 2026
This section covers the Sapilumen website and does not change the description of data collection in the Android application. Google Analytics 4 and Yandex Metrica load on public website pages after you choose Accept all. Before that choice, or when you choose Essential only, the website does not load their scripts or send requests to them.
The tags help us measure visits and improve pages. They process information about viewed pages, traffic sources, the browser and device, and actions on the website. Yandex Metrica includes a click map, link tracking, an accurate bounce rate and Session Replay. Session Replay records actions and page content to replay visits; recordings are available in Metrica for 15 days, including the current day.
Your choice is saved for 180 days and can be changed through the cookie settings. If you choose Essential only or reset your choice after analytics has started, the website stops the tags in the current tab, removes some accessible analytics cookies and local-storage entries, and reloads the page. Reload other open tabs separately. This does not cancel requests already sent or delete data held by providers or cookies on Yandex domains.
Analytics cookies, storage periods and provider documentation
Local data storage
The app keeps your learning progress, practice results and settings in local storage until you clear the app's storage in Android settings or uninstall the app. Resetting progress clears your current learning results.
If your app version and device support Android system backup, the system may include some app data in a backup. If your device uses Google's cloud backup service, that copy is linked to your Google Account. Android may also transfer app data directly between devices during setup. Cloud backup and direct device transfer are separate system functions. Their availability and scope depend on the Android version, device manufacturer, app configuration and your backup or transfer settings. Sapilumen does not provide its own cloud synchronisation for this data.
Data from an available backup may be restored when you reinstall the app, set up a new device or set up a device after a factory reset. Backup and restoration are not guaranteed on every device.
Google determines the storage and deletion periods for copies held by its backup service. Sapilumen does not set those periods or have direct access to those copies. See Google's instructions for managing Android backups.
Audio
The application uses local audio files supplied with the installation and played directly on the device. Playback does not require an internet connection, and we do not record or transmit your voice. Speech audio is synthesised with VOICEVOX.
Google Play
When you install or update the app through Google Play, Google's privacy terms apply to data processed by the store.
Google's Android system backup service operates separately from the Google Play store. Data processed by that service is covered by the Google Privacy Policy.
Technologies and attribution
We are grateful to openly licensed projects that make the application possible. The attribution below is included in accordance with the applicable licence.
Speech is synthesised with VOICEVOX using the 春日部つむぎ (Kasukabe Tsumugi) voice.
How to delete data
Resetting progress, clearing the app's storage and uninstalling the app affect data stored locally on your device. These actions do not guarantee deletion of a previously created system backup. If a copy remains, Android may restore it during a later installation or device setup.
To manage or delete a backup held in your Google Account, use Google's backup controls and official deletion instructions.
- Reset progress in the app. Use the reset option in app settings to clear your current learning results.
- Clear the app's storage in Android settings. This removes the app's local data and settings. Menu names vary by device.
- Uninstall the app. This removes data from the app's own storage on that device.
- Manage system backups separately. Sapilumen cannot delete those copies in response to a support request. Check the scope before confirming: backup controls can affect other apps, and the Google Account dashboard's Delete all data option covers device and WhatsApp backups across the account.
Changes to this policy
We may update this policy as features are added, for example if accounts, synchronisation or analytics are introduced. The date at the top of this document will be updated when material changes are made.
Contact
For questions about privacy or data processing, email us at support@sapilumen.com.