Examine source code of Somiibo

{
  "name": "__MSG_appName__",
  "version": "1.0.6",
  "manifest_version": 2,
  "description": "__MSG_appDescription__",
  "icons": {
    "16": "icons/icon-16.png",
    "128": "icons/icon-128.png"
  },
  "default_locale": "en",
  "background": {
    "page": "background.html"
  },
  "permissions": [
    "tabs",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/contentscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_icon": {
      "19": "icons/icon-19.png",
      "38": "icons/icon-38.png"
    },
    "default_title": "Somiibo",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "support@somiibo.com",
      "strict_min_version": "58.0"
    }
  },
  "content_security_policy": "script-src 'self' https://www.gstatic.com/ https://*.firebaseio.com https://www.googleapis.com https://apis.google.com https://cdn.jsdelivr.net https://cdn.socket.io 'unsafe-eval'; object-src 'self'",
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoXp/7Mw7ajMPznKRMEyN4rPXkSOOtyZlszLF8HWsgz/+vkzAH9UpbUZLGbM44rPYqeD1xiKaHHBMN9WemYJ4dqq3ZBJHWcRTImMJXZdulmMZIt/vJrBLgfBweKHmDfnciJ1ZpfdaugfOGQYjeaVCB7B1ZJa0jl7qJfMpurESw2ITahuPiAklfqXJOSuYL9h8EhmE7Us+CbGh0ZzKMmc53YWj36TBhu+oazUGpYbd3KOp9DVa6Jvj73aBBRd/fL7BmUu2lKKqj/1ZRwpHDS6awId1BYBbZ+jPtc2/gq2lWdO/ZGchb/dj7IbWTK95TeXOb9HmpIxlNKn5Ci5WFhx85QIDAQAB",
  "applications": {
    "gecko": {
      "id": "my-app-id@mozilla.org"
    }
  }
}