Examine source code of SEOInfo

{
  "manifest_version": 2,
  "name": "SEOInfo",
  "description": "__MSG_extension_description__",
  "author": "Weeblr",
  "homepage_url": "https://weeblr.com/seoinfo",
  "version": "2.2.0.447",
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "seoinfo@weeblrpress.com",
      "strict_min_version": "61.0"
    }
  },
  "icons": {
    "48": "/assets/default/images/icons/seoinfo-48.png"
  },
  "permissions": [
    "tabs",
    "webNavigation",
    "webRequest",
    "*://*/",
    "<all_urls>",
    "storage"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_action": {
    "default_title": "SEOInfo",
    "default_icon": "/assets/default/images/icons/seoinfo-32.png",
    "default_popup": "/html/popup.html"
  },
  "background": {
    "page": "/html/background.html",
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "/app/content.js"
      ]
    }
  ]
}