Examine source code of SERP Preview Tool

{
  "manifest_version": 2,
  "name": "SERP Preview Tool",
  "version": "1.0",
  "description": "Preview how your page appears in search engine results.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b9bfda60-057f-4e49-9a1f-c36df261aeee}"
    }
  }
}