Examine source code of sch0ngesehen

{
  "name": "sch0ngesehen",
  "description": "Erweiterung für pr0gramm.com. Markiert bereits gesehene Bilder.",
  "version": "1.1",
  "icons": {
    "128": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://pr0gramm.com/*"
      ],
      "css": [
        "marker.css"
      ],
      "js": [
        "sch0ngesehen.js"
      ]
    }
  ],
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{a144cc95-b099-4fcd-b575-d7b847ba45ae}"
    }
  }
}