Privacy Policy for HeadLink

1. Camera and Face Tracking Data

• What we collect: HeadLink uses your device's front-facing camera to track head movements and facial position through Apple's ARKit framework
• How it's processed: Face tracking data (pitch, yaw, roll, and position coordinates) is processed locally on your device
• Purpose: To provide real-time head tracking functionality for Opentrack integration
• Storage: Face tracking data is not stored permanently and is only processed in real-time for transmission

2. Network Configuration Data

• What we collect: IP addresses and port numbers you configure for Opentrack connections
• How it's stored: This information is stored locally in your device's user preferences (UserDefaults)
• Purpose: To establish UDP connections with Opentrack software on your computer
• Access: Only you can view and modify this information through the app's settings

3. Trial and Purchase Information

• What we collect:
  • Trial start time and duration
  • Trial extension usage status
  • Purchase verification status for the full version
• How it's stored: Securely stored in your device's iOS Keychain using encryption
• Purpose: To manage the 24-hour trial period and track full version purchases

4. App Usage and Performance Data

• What we collect:
  • Connection status logs
  • AR session state information
  • Error logs for troubleshooting
• How it's processed: Logged locally using Apple's os.log framework
• Purpose: For app functionality, debugging, and performance optimization
• Storage: Logs are stored locally and may be included in iOS diagnostic reports if you choose to share them with Apple

Information We Collect

Our app uses your device's TrueDepth camera system to collect:

• Head position coordinates (X, Y, Z spatial location)
• Head orientation angles (pitch, yaw, roll rotations)
• 3D facial geometry data for mesh visualization
• Face detection and tracking status

Purpose of Collection

Face data is collected solely to:

• Provide real-time head tracking functionality
• Transmit head movement data to OpenTrack-compatible applications
• Display optional visual feedback through face mesh overlay
• Enable natural head movement input for gaming and simulation applications

Data Processing and Storage

• All face data is processed locally on your device in real-time
• No face data is permanently stored, saved, or cached
• Data exists only in device memory during active tracking sessions
• No face data is uploaded to servers or cloud services
• All data is immediately discarded when tracking stops

Data Sharing

• Only processed head pose coordinates (6 numerical values) are transmitted via UDP to your configured local network endpoint
• No face data is shared with third parties, advertisers, or analytics services
• You control exactly where tracking data is sent through IP address and port configuration
• No raw facial imagery or biometric identifiers are ever transmitted

Your Control

• Face tracking requires explicit camera permission
• You can stop tracking immediately by closing the app
• You control network transmission through settings
• Face mesh visualization can be disabled in settings

Real-Time Processing

• Face tracking data is processed in real-time to calculate head position and orientation
• Data is immediately transmitted via UDP to the IP address you specify
• No facial recognition or biometric identification is performed

Local Storage Only

• All configuration settings are stored locally on your device
• Trial and purchase information is stored securely in your device's Keychain
• No personal data is transmitted to our servers

Opentrack Integration

• Head tracking coordinates are sent to Opentrack software via UDP protocol
• You control the destination IP address and port
• Data transmission only occurs to addresses you explicitly configure

No Third-Party Sharing

• We do not share, sell, or transmit your personal information to third parties
• Face tracking data is only sent to Opentrack destinations you configure
• All processing occurs locally on your device

Apple Services

• In-app purchases are processed through Apple's App Store using StoreKit
• Apple handles all payment processing according to their privacy policy
• We do not receive or store payment information

Local Processing

• All face tracking occurs on-device using Apple's ARKit framework
• No facial data is uploaded to external servers
• Camera access is used only for real-time head tracking

Secure Storage

• Trial and purchase data is encrypted and stored in iOS Keychain
• Configuration settings use iOS standard secure storage mechanisms
• No sensitive data is stored in plain text

Network Security

• UDP transmissions are sent only to addresses you specify
• No automatic data collection or transmission occurs
• You maintain complete control over data destinations

Camera Access

• You can revoke camera access at any time through iOS Settings
• The app will not function without camera access for face tracking
• No images or videos are recorded or stored

Data Control

• You can reset your trial data through debug options (in development builds)
• Configuration settings can be modified or reset through the app's settings
• Purchase data is managed through your Apple ID account

Data Deletion

• Uninstalling the app removes all locally stored data
• iOS Keychain data may persist and can be removed through iOS settings
• No server-side data exists to delete

Camera Permission

• The app requests camera access for face tracking functionality
• Camera data is processed in real-time and not recorded
• Usage description: "Head tracking requires access to the camera"

ARKit Processing

• Face tracking uses Apple's ARKit Face Tracking configuration
• Only facial landmarks and head orientation are processed
• No facial recognition or identity verification is performed

Face Mesh Visualization

• Optional face mesh overlay for visual feedback
• Rendered locally on your device for user interface purposes
• No mesh data is transmitted or stored

Purchase Information

• Managed through Apple's App Store Connect
• Purchase verification handled by Apple's StoreKit framework
• We store only the verification status of your purchase locally

Trial System

• 24-hour trial period with optional 24-hour extension
• Trial data stored securely in iOS Keychain
• Purchase status overrides trial limitations

Temporary Data

• Face tracking data: Processed in real-time, not stored
• Network data: Transmitted immediately, not retained
• Logs: Stored locally for debugging, rotated by iOS

Persistent Data

• App settings: Retained until app deletion
• Trial information: Stored in Keychain until manually cleared
• Purchase status: Managed by Apple's systems

Network Communication

• Protocol: UDP (User Datagram Protocol)
• Data format: Binary head pose data (48 bytes)
• Transmission rate: Up to 60 FPS
• Destination: User-configured IP addresses only

Data Format

The app transmits the following data structure:

Where:

• x, y, z: Head position coordinates
• yaw, pitch, roll: Head orientation in degrees