Examine source code of Microdata Implementer

{
  "manifest_version": 2,
  "name": "Microdata Implementer",
  "version": "1.3",
  "description": "Inject Microdata structured data into websites for SEO testing.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/logo_64.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "inject.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ebba7bb8-8c87-45e0-be66-a6b76666b5cc}"
    }
  }
}