Examine source code of TabTimeStat

{
  "manifest_version": 2,
  "name": "TabTimeStat",
  "version": "1.0",
  "description": "Track time spent on websites with detailed stats.",
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon64.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "alarms"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1c6ea339-31d1-4455-8058-235e0200a5f5}",
      "strict_min_version": "103.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}