Examine source code of FreeTheGTree

{
  "content_scripts": [
    {
      "css": [
        "ext.css",
        "PopOverView.css"
      ],
      "js": [
        "jquery-3.4.1.min.js",
        "ITP_ProgressBar.js",
        "PopOverView.js",
        "RePostAdProcess.class.js",
        "managead.js"
      ],
      "matches": [
        "https://my.gumtree.com/manage/ads*"
      ]
    },
    {
      "css": [
        "ext.css",
        "PopOverView.css"
      ],
      "js": [
        "jquery-3.4.1.min.js",
        "PopOverView.js",
        "postad.js"
      ],
      "matches": [
        "https://my.gumtree.com/postad*"
      ]
    }
  ],
  "description": "Towards a better Gumtree",
  "icons": {
    "128": "tree128.png"
  },
  "manifest_version": 2,
  "name": "FreeTheGTree",
  "permissions": [
    "https://freethetree.co.uk/*",
    "https://www.gumtree.com/*",
    "storage",
    "https://i.ebayimg.com/*",
    "webRequest"
  ],
  "version": "1.6.2",
  "web_accessible_resources": [
    "*"
  ],
  "applications": {
    "gecko": {
      "id": "contact@freethetree.co.uk"
    }
  }
}