Examine source code of Broken Links Detector

{
  "manifest_version": 2,
  "name": "Broken Links Detector",
  "version": "1.1",
  "description": "Detect broken (404, 500) links on the current website.",
  "icons": {
    "64": "icons/logo_64.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "http://*/",
    "https://*/"
  ],
  "browser_action": {
    "default_title": "Check Broken Links",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9136cf34-9dc0-4bbe-acec-a3d07b1ce247}"
    }
  }
}