Background User Activity Tracking APK

I'm seeking a skilled Android developer to create an APK which operates discreetly in the background, tracking user activity. The application should be designed to operate without generating any errors or warnings.

Key Features:
- Background operation: The APK must run in the background, undetectable by the user.
- User activity tracking: The primary purpose of the APK is to monitor and record user interaction with the device.

Ideal Skills:
- Proficiency in Android development and APK creation
- Experience with background service development
- Understanding of user privacy and ethical programming
- Ability to write clean, error-free code.

Please note: This project does not involve tracking location data or monitoring system activity. It is strictly focused on user activity tracking.