Examine source code of 4chan Scroller

{
  "manifest_version": 2,
  "name": "4chan Scroller",
  "version": "1.0.3",
  "description": "Adds media scrolling features to 4chan.",
  "icons": {
    "48": "icons/border-48.png",
    "96": "icons/border-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "4chanscroller@geniedev"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.4chan.org/*",
        "*://*.4channel.org/*"
      ],
      "js": [
        "main.js"
      ]
    }
  ]
}