Examine source code of Tab Time Tracker is

{
  "manifest_version": 2,
  "name": "Tab Time Tracker",
  "version": "1.0",
  "description": "Theo dõi thời gian sử dụng trên mỗi tab",
  "permissions": [
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png"
    }
  },
  "icons": {
    "16": "icon.png",
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3e49e393-b048-438a-8e1a-356967daf597}"
    }
  }
}