WalkingBud Privacy Policy

Last updated: April 2026 · Effective immediately upon installation

Short version: WalkingBud stores your fitness data on your device only. No data is ever sent to our servers — because there are no servers. The only way data leaves your device is if you explicitly initiate a Google Drive backup or a CSV/JSON export.

1. Who We Are

WalkingBud is a personal fitness application for Android that connects to WalkingPad treadmills over Bluetooth Low Energy (BLE). The app is developed and maintained by an individual developer. There is no company, no back-end infrastructure, and no cloud service operated on behalf of users.

2. Data We Collect and Store

2.1 Body Profile

When you set up the app you provide:

Height (cm)
Weight (kg)
Optionally: a manual step-length override (cm) or calibration coefficients generated by the in-app calibration wizard

This information is used exclusively to estimate step length and calorie burn. It is stored locally on your device in Android's SharedPreferences. It is never transmitted to any server.

2.2 Workout / Session History

For each completed treadmill session the app stores:

Start and end time
Total distance (km), average speed, maximum speed
Step count (estimated + any manual correction you enter)
Duration (total and active)
Calories burned (estimated)
An optional free-text note you write yourself
A delta-event log of speed and incline changes during the session
A randomly generated session ID (UUID, not linked to your identity)

All session data is stored locally on your device. No name, email address, phone number, GPS location, or device identifier is included in any session record.

2.3 Fitness Goals and App Settings

Daily and weekly step/distance/time targets, display preferences (theme, language, week start day), and feature toggles are stored locally in SharedPreferences. None of this data is transmitted anywhere.

2.4 Bluetooth Device Identifier

The Bluetooth remote device ID of your treadmill is stored locally so the app can reconnect to the same device automatically on the next launch. This identifier is never transmitted off your device.

2.5 BLE Diagnostic Log

A ring-buffer of up to 200 lines of raw BLE packet data (hex values and decoded metrics) is kept in RAM only and is never written to disk automatically. It can be shared manually via the Diagnostics screen; doing so shows a privacy-warning dialog requiring your explicit confirmation first.

3. Data That Leaves Your Device

No data leaves your device automatically or silently. The only situations in which your data travels outside the device are described below, and each requires your deliberate action.

3.1 Google Drive Backup (optional, user-initiated)

If you sign in with a Google account and enable the backup feature, the app uploads a single JSON file to your own Google Drive hidden app data folder (appDataFolder scope). This folder is:

Not visible in the Google Drive user interface
Not accessible by other apps
Automatically deleted if you uninstall WalkingBud or revoke its Google Drive access

The backup file contains your body profile, goals, and complete session history (identical to what is stored locally). It does not contain your Google account name or any other Google account information.

The Google OAuth scope used is: https://www.googleapis.com/auth/drive.appdata — the narrowest available scope that allows app-data backup without accessing your files or any other Drive content.

Your Google account email address is displayed in the Settings screen so you know which account is connected. It is stored locally and is cleared when you sign out. Signing out calls GoogleSignIn.disconnect(), which revokes the OAuth token and removes WalkingBud from your authorised apps.

Auto-backup (if enabled) fires automatically after each completed workout session. You can disable it at any time in Settings → Backup. Backups are governed by Google's Privacy Policy.

3.2 CSV / JSON Export (optional, user-initiated)

You can export your session history as a CSV or JSON file from the History screen. The app writes a temporary file and opens the Android system share sheet, allowing you to send it to any app you choose (e-mail, cloud storage, messaging, etc.). WalkingBud itself does not decide where the file goes — that is entirely your choice.

3.3 Google Health Connect (optional, on-device)

If you enable Health Connect sync, WalkingBud writes workout and step data to Google Health Connect after each session. Health Connect is an on-device Android store — this is not a network operation performed by WalkingBud, and WalkingBud never reads data from Health Connect. Once the data is in Health Connect, its further use is governed by Google's Health Connect policies and whatever other apps you have authorised in the Health Connect settings on your device.

Data written to Health Connect per session:

Workout (exercise type: walking, start/end time, distance, calories)
Step count (respects any manual correction you have entered)
Floors climbed (only when incline > 0; derived from incline data)

4. Android Permissions

Permission	Why it is needed
`BLUETOOTH_SCAN` `BLUETOOTH_CONNECT`	Required to discover and communicate with your WalkingPad treadmill over BLE. The `neverForLocation` flag is set on BLUETOOTH_SCAN — location is never inferred from BLE.
`ACCESS_FINE_LOCATION` `ACCESS_COARSE_LOCATION`	Required by Android versions below 12 (API 31) to perform BLE scanning. This permission is not requested on Android 12 and above. WalkingBud does not use location data for any purpose.
`FOREGROUND_SERVICE` `FOREGROUND_SERVICE_CONNECTED_DEVICE`	Runs a foreground service to keep the BLE connection alive when the screen is off, ensuring uninterrupted session recording.
`POST_NOTIFICATIONS`	Shows a persistent session notification with Pause / Resume / Stop controls (required on Android 13+).
`WAKE_LOCK`	Keeps the screen on during an active training session (if the "Keep screen on" setting is enabled).
`ACTIVITY_RECOGNITION`	Required by the Health Connect API to write step data. The app does not use the device's motion sensors for step detection.
Health Connect write permissions	Allow writing workout, step, calorie, distance, and floor-climb data to the Health Connect store. Only requested if you enable Health Connect sync.

5. Third-Party SDKs and Services

Service / SDK	Purpose	Data shared
Google Drive API (`googleapis`)	Optional cloud backup to your own Drive account	Body profile, goals, session history — only when you initiate a backup
Google Sign-In	Authentication for Drive backup	OAuth token used to write to your app-data folder; email displayed in Settings UI only
Google Health Connect	Optional on-device fitness data store	Workout, steps, calories, floors — written on-device only

WalkingBud contains no analytics SDKs, no advertising SDKs, no crash-reporting services, and no tracking pixels. All debug logging is gated by debug mode and stays on-device.

6. Data Retention and Deletion

All data is stored on your device and is under your control at all times:

You can delete individual sessions from the History screen.
You can clear your entire session history from Settings → Reset → Delete all training history.
You can clear your calibration data from Settings → Step calibration → Clear calibration.
You can reset your profile, goals, and presets to defaults from the Settings screen.
Uninstalling the app removes all locally stored data.
If you enabled Google Drive backup, you can delete the backup file from your Google Drive settings (Manage Apps in Google Drive), or by signing out from within the app, then revoking access in your Google account permissions.

7. Children's Privacy

WalkingBud is not directed at children under 13 years of age. The app does not knowingly collect personal information from children. If you believe a child has provided personal information through the app, please contact us and we will promptly delete it.

8. Changes to This Policy

If we make material changes to this privacy policy, we will update the "Last updated" date at the top of this page and, where appropriate, provide additional notice within the app. Continued use of the app after changes take effect constitutes acceptance of the updated policy.

9. Contact

If you have any questions or concerns about this privacy policy or WalkingBud's data practices, please open an issue on the GitHub repository.