LK Health

Privacy Policy

Effective date: 4 November 2026 (applies to LK Health 1.0.5 and later)
Provider: LK Studio JP ("we", "us")
Website: lks-jp.tech　Contact: feedback site

1. Summary

LK Health is a health-tracking app that works offline on your phone. We have no server and no user accounts. The app has no internet permission and cannot send your data anywhere. We do not collect, receive or store your personal information.

This policy explains what the app stores on your phone, which permissions it uses, and how you can manage and delete your data.

2. What we do not collect

• We collect no personal information, including names, health data, location and device identifiers.
• The app has no ads and no analytics, crash-reporting or tracking SDKs.
• We do not sell, rent or share your data with anyone.

3. Data stored on your phone

The following data is kept only in the private storage Android gives this app. Other apps cannot read it.

• Profile: name (optional), sex, birth year, height, weight and goals.
• Your answers to the ASABA Assistant and sleep questionnaires, including any health conditions and exercise limits you choose.
• Food log and foods you create.
• Steps, weight and heart-rate readings.
• Workouts: time, energy, heart rate, and GPS routes of outdoor workouts.
• Sleep records, and sleep-probability readings if you turn on sleep detection on the phone.
• Training plan, reminders, app settings, and offline map files you import.
• Error reports (see section 9).

4. Permissions and why

• Location (precise / approximate): Used only after you start recording an outdoor workout, to measure distance, pace and the route. Recording runs as a foreground service with a visible notification. The app does not ask for background location. On Android 11 and older, scanning for Bluetooth heart-rate devices also needs the location permission.
• Physical activity: To count steps with the phone's step sensor, and for sleep detection on the phone if you turn it on.
• Nearby devices (Bluetooth): To receive the standard heart-rate broadcast from a watch or chest strap.
• Health Connect: Read only; see section 5.
• Notifications: Training reminders, and the status notification while an outdoor workout is recording.
• Biometrics: Used only if you unlock the app lock with fingerprint or face. Android performs the check; the app never receives biometric data.
• Other: Setting reminders again after the phone restarts; a foreground service while an outdoor workout is recording; vibration for reminders. The "view network connections" and "prevent phone from sleeping" permissions in the app package are declared by Android's WorkManager component and are used only to schedule background tasks (such as step logging and automatic export). The app itself has no internet permission.

5. Health Connect data

With your permission, LK Health reads steps, weight, heart rate, resting heart rate, exercise sessions, active calories and sleep from Health Connect. This data is usually written there by a watch or another health app.

• It is used only to show your records in the app, to calculate energy and scores, and to remove duplicates.
• It is not used for advertising, not sold or transferred, and not sent to anyone.
• The app writes nothing to Health Connect.
• You can withdraw permission in Health Connect at any time.

6. Sleep detection on the phone (optional, off by default)

When you turn it on, Google Play services on the phone estimate sleep from movement, ambient light and screen use. LK Health receives only the sleep and wake times and a sleep probability about every 10 minutes, and keeps them on your phone. The probability readings are deleted automatically after about two months. Turning the switch off stops the detection.

Google Play services are a component provided by Google, and their own data processing is covered by Google's privacy policy (https://policies.google.com/privacy).

7. Location data

GPS positions are stored on your phone only as the routes of the outdoor workouts you record, and are never sent anywhere. Deleting a workout also deletes its route.

8. Imported maps

Offline maps are files you import yourself. Their content (such as place names, borders and labels), their accuracy and their licence are your responsibility, and they do not represent the position of LK Studio JP. LK Studio JP does not supply, check or endorse imported maps.

The attribution stored in a map file is shown on the map, as map licences usually require. Imported maps are kept in the app's private storage and are not included in backups.

9. Error reports

If the app crashes, it saves an error report (the error, app version, Android version and device model) in its private storage and shows it the next time you open the app. It leaves the phone only if you choose to share or copy it. Closing the report deletes it.

10. Backup and export

• Android backup: If Android backup is turned on on your phone, Android can back up the app's database and settings to your own Google account. On Android 9 and later, on a phone with a screen lock, this backup is end-to-end encrypted. You can leave LK Health out of it in the app under Me › Backup and restore. We have no access to this backup.
• Exported files: Exported files are saved where you choose, and keeping them safe is then your responsibility. You can protect an export with a password (AES-256 encryption); without the password it cannot be opened.

11. Retention and deletion

• Your data stays on your phone until you delete it.
• In the app, "Delete all data" under Me › About and privacy deletes all records, settings and imported maps. You can also delete records one by one.
• Uninstalling the app, or clearing its storage in Android settings, deletes everything the app stored.
• Copies in your Google backup or in files you exported are not deleted by this; delete them in your Google account or where the files are kept.

12. Security

Data is kept in the private storage Android gives each app. You can turn on an app lock (PIN or biometrics) and protect exports with a password. Because the data stays on your device, its screen lock and system updates matter too.

13. Your rights

We hold no personal information about you, so we cannot access, correct or delete it on your behalf. You can view, change, export and delete all of your data in the app at any time. Backups in your Google account are managed in your Google account.

14. Children

LK Health collects no personal information from anyone, including children. Users under 18 should use the app with guidance from a parent or guardian.

15. Health information

The scores, assessments and suggestions in the app are for everyday wellbeing. They are not a medical diagnosis or treatment. If you feel unwell or have questions about your health, please talk to a doctor.

16. Changes to this policy

If we change this policy, we will update this page and the effective date above, and the updated text will also come with an app update.

17. Contact

Questions about this policy can be sent to LK Studio JP through the feedback site.

• This policy: https://lks-jp.tech/en/lk-health/privacy/