- Fixed the issue of unable to clear user preferences about the tab due to incorrect declaration of storage type.

This version is intended for testing only as the uploaded 1.3 version does not work as expected.

Changes:
Previous version:
- Timeout request will be cleared until the next reload.

Current version:
- Timeout request and user preferences about the tab will be cleared right away after closing the tab.
- Fixed memory leak issue due to continuously adding tab closed listener from the function handled by setTimeout.

Correct the description and homepage in manifest.json.