Privacy Policy

TK4BL

Last Updated: November 10, 2025

1. Purpose of Collection and Use of Personal Information

TK4BL collects and uses personal information for the following purposes:

AVC (App Volume Control)

  • Providing App Features: Storing and applying settings for per-app volume control.
  • Error Resolution: Collecting error reports and diagnostic information to improve app stability.
  • Service Improvement: Enhancing service quality through user feedback.

Knitting

  • Providing App Features: Storing and managing yarn inventory data including photos, specifications, and usage records.
  • Photo Management: Capturing, storing, and editing yarn photos for inventory purposes.
  • Error Resolution: Collecting error reports and diagnostic information to improve app stability.
  • Service Improvement: Enhancing service quality through user feedback.

2. Items of Personal Information Collected

Common

  • Personally Identifiable Information, Sensitive Personal Information: Not collected

AVC (App Volume Control)

  • App Settings
    • Volume UI display type, coordinates (X,Y), and size settings
    • Whether to display on manual volume change
    • Whether to display app name on detection
    • Landscape mode coordinates and separate setting usage
    • Font size and overlay display time
    • Volume display mode settings
    • Debouncing activation and delay time settings
  • Error Logs: Information on errors and exceptions occurring during app execution.
  • Device Information: App version, device model, Android version, etc.
  • User Feedback: Additional explanatory content entered by the user when reporting an error.
  • Permissions
    • Accessibility Service (AccessibilityService)
      • Purpose: Used to detect app activity in real-time to use the 'per-app volume control' feature.
      • This information is processed only on the device.
      • However, when using the 'error reporting' feature, with user consent, the active app name and package name detected and collected through this permission are transmitted to the developer.
    • Installed Apps List (QUERY_ALL_PACKAGES)
      • Purpose: Due to app functionality characteristics, the list of installed apps is collected in advance to prevent device overheating and battery consumption.
      • This information is processed only on the device.
    • Display Over Other Apps (SYSTEM_ALERT_WINDOW)
      • Purpose: Used to display app names and volume values on the screen when active app detection or volume changes occur.
      • This information is processed only on the device.
      • However, when using the 'error reporting' feature, with user consent, app names and volume values from the information displayed through this permission are transmitted to the developer.

Knitting

  • Yarn Inventory Data: Yarn specifications, photos, usage records, and inventory information entered by the user.
  • Error Logs: Information on errors and exceptions occurring during app execution.
  • Device Information: App version, device model, Android version, etc.
  • User Feedback: Additional explanatory content entered by the user when reporting an error.
  • Permissions
    • Camera (CAMERA)
      • Purpose: Used to capture photos of yarn for inventory management and record-keeping.
      • This information is processed only on the device.

3. Method of Collection

  • Automatic Collection: Information collected automatically during app usage.
  • Manual Input: Settings and feedback directly entered by the user.
  • Permission-Based: Information collected based on user consent.

4. Retention and Use Period

  • App Settings: Until the app is deleted.
  • Error Logs: Deleted within 30 days after error resolution.
  • User Feedback: Deleted within 1 year after processing.
  • Device Information: Until the app is deleted.

5. Provision of Personal Information to Third Parties

TK4BL provides personal information to third parties only in the following cases:

  • With user consent.
  • When required by law.
  • Providing anonymized information to Firebase Crashlytics for error analysis.

6. Measures for Securing Personal Information

  • Encryption: Storing important information encrypted.
  • Access Control: Restricting access rights to personal information.
  • Secure Transmission: Secure data transmission via HTTPS.
  • Regular Inspection: Regular checks on personal information protection status.

7. User Rights

Users have the following rights:

  • Right to request access to personal information.
  • Right to request correction or deletion of personal information.
  • Right to request suspension of processing of personal information.
  • Right to request data portability.

8. Changes to the Privacy Policy

In the event of changes to the Privacy Policy, the changes will be announced through in-app notifications and the Privacy Policy itself.

9. Personal Information Protection Officer & Inquiries

TK4BL has designated a Personal Information Protection Officer to oversee tasks related to personal information processing and to handle complaints and remedy damages for data subjects. If you have any inquiries, please contact us below.

  • Personal Information Protection Officer: TK4BL
  • Email: tkforbl@gmail.com
  • Processing Period: We will respond within 14 days of receipt.

Important Notice

  • This Privacy Policy governs the collection and use of personal information for TK4BL apps (AVC and Knitting).
  • By agreeing to this policy, the user is deemed to have consented to the collection and use of personal information.
  • Please feel free to contact us at any time with inquiries related to personal information processing.