Examine source code of SEO Inspector

{
  "manifest_version": 2,
  "name": "SEO Inspector",
  "version": "0.1.7resigned1",
  "browser_action": {
    "default_icon": "icon2.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "script/lib/jquery-3.2.1.min.js",
        "script/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{56573d6c-784b-48e0-802f-021f3e3910af}"
    }
  }
}