Examine source code of Esconde smurf

{
  "manifest_version": 2,
  "name": "NoSmurfs",
  "version": "1.1",
  "description": "esconde salas do lobby que contenham players que tenham KDR maior do que do filtro.",
  "icons": {
    "48": "icons/gcutils48.jpg",
    "96": "icons/gcutils96.jpg"
  },
  "browser_action": {
    "default_icon": "icons/gcutils48.jpg",
    "default_title": "Filtro de KDR!",
    "default_popup": "popup/config.html"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.gamersclub.com.br/lobby"
      ],
      "js": [
        "gcutils.js"
      ]
    }
  ],
  "applications": {
    "gecko": {
      "id": "caiomassan00@gmail.com"
    }
  }
}