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Privacy Policy

Last updated: June 16, 2026

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

In short, the current version of the application does not collect personal data. It is intentionally designed to work without user accounts or our own servers.

Local data storage

Your progress, completed topics, practice results and settings are stored directly in device memory. They are not sent to our servers and are available only on that device. Reinstalling the application or clearing its data removes the locally stored progress.

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

The application is distributed through Google Play. Google’s privacy terms apply when the application is installed or updated and to any future store purchases. Processing performed by the application store is controlled by Google; see 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.

Voice synthesis

Speech is synthesised with VOICEVOX using the (Kasukabe Tsumugi) voice.

How to delete data

Because progress is stored only on your device, you remain in control of it. Local progress can be removed in either of the following ways:

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 [email protected].