Examine source code of RTP Download

{
  "manifest_version": 2,
  "name": "RTP Download",
  "description": "Get the link for download video in RTP web page",
  "version": "1.1resigned1",
  "author": "Antonio Oliveira",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Obter link"
  },
  "permissions": [
    "activeTab",
    "https://rtp-downloader.herokuapp.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0dd56a69-0ca9-41e1-a3ea-f9c1c8f10e90}"
    }
  }
}