Examine source code of WIXtension

{
  "manifest_version": 2,
  "name": "WIXtension",
  "version": "0.2.2.1",
  "description": "Submits market prices of the browser game 'Wurzelimperium' to the 'Wimp Calculator' on http://wimprechner.no-ip.info",
  "icons": {
    "48": "icons/favicon48.png"
  },
  "permissions": [
    "*://wimprechner.no-ip.info/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.wurzelimperium.de/*"
      ],
      "js": [
        "wixtension.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ]
}