Privacy Policy

1. Introduction

This Privacy Policy explains how stackd ("we", "us", or "our") handles your data when you use the stackd Android application. We believe your workout data belongs entirely to you. Our architecture enforces data sovereignty by keeping all workout logs, custom routines, and exercise histories stored locally on your device.

2. Data We Store Locally on Your Device

All data created while using stackd is saved exclusively in your device's private SQLite database (via Android Room). This includes:

• Workout Sessions & Logs: Start and end timestamps, exercises performed, set counts, weight (kg), repetitions, Rate of Perceived Exertion (RPE), and workout notes.
• Workout Routines: Custom templates, exercise sequences, and target sets created by you.
• Custom Exercises: Names, target muscle groups, and movement instructions for exercises you create.
• App Preferences: Display preferences and sync settings (such as Health Connect toggle).

This data never leaves your device unless you explicitly export a manual backup file.

3. Google Health Connect Integration

stackd offers optional integration with Android Health Connect (androidx.health.connect:connect-client), allowing you to sync completed workouts with your unified Android health profile (e.g. Google Fit, Samsung Health).

• Write-Only Permission: We request only android.permission.health.WRITE_EXERCISE. When granted, stackd writes completed strength and calisthenics workout records (session title, start/end time, and exercise category) to your local Health Connect provider.
• Zero Health Data Reading: stackd does not request, access, read, or process any other health data from Health Connect (such as heart rate, sleep cycles, biometric vitals, or external medical records).
• Health Connect Policy Compliance: In accordance with Google Health Connect Developer Permissions policies, data transferred to Health Connect is strictly user-directed, stored locally by the Android operating system, and is never used for advertising, credit scoring, or shared with third parties.

4. Backups & Storage Access Framework (SAF)

stackd includes an explicit manual backup feature allowing you to export and import portable JSON backup files (stackd_backup_YYYY-MM-DD.json).

• We utilize Android's secure Storage Access Framework (SAF).
• stackd does not require or request broad device storage permissions (e.g., READ_EXTERNAL_STORAGE or MANAGE_EXTERNAL_STORAGE are not declared).
• You retain complete control over where backup files are saved (such as Google Drive, local storage, or removable media).

5. Customer Support & Diagnostics

When you choose to tap "Contact Support" within the app:

• stackd opens your device's default email client addressed to oyvind.volden+stackd@gmail.com via a standard ACTION_SENDTO mailto intent.
• To assist with troubleshooting, technical device metadata (app version, Android OS version, device model, and database schema version) is prefilled into the email draft.
• You have full control: You can review, edit, or delete any of this diagnostic information before hitting send. No communication occurs in the background without your knowledge and manual confirmation.

6. Analytics, Tracking & Advertising

stackd contains:

• NO third-party analytics SDKs (no Firebase Analytics, Google Analytics, Mixpanel, etc.).
• NO crash-reporting telemetry daemons.
• NO advertising networks or tracking cookies.
• NO background internet permissions declared in the Android Manifest.

7. Data Retention & Deletion

Because your data is stored strictly on your local device:

• You can delete individual exercises, routines, or workout sessions directly in the app at any time.
• You can restore or overwrite your training database via the Backup settings card.
• Uninstalling stackd or clearing the app storage in your Android System Settings immediately and permanently deletes all local data and preferences.

8. Children's Privacy

stackd does not collect personal information from any individuals, including children under the age of 13. The application is suitable for general audiences seeking offline workout tracking.

9. Changes to this Privacy Policy

We may update this Privacy Policy from time to time to reflect changes in functionality or legal requirements. Any updates will be published on this page with an updated "Last updated" date.

10. Contact & Legal Entity Information

If you have any questions, feedback, or concerns regarding this Privacy Policy or your privacy in stackd, please reach out to:

Publisher / Legal Entity: Volden
Organization Number: 925 411 337 (Brønnøysundregistrene, Norway)
D-U-N-S®: 347042965
Contact Person: Øyvind Volden
Email: oyvind.volden+stackd@gmail.com
Website: https://stackd.volden.family/