Examine source code of Yeargrounds

{
  "manifest_version": 2,
  "name": "Yeargrounds",
  "version": "1.0",
  "description": "Search Newgrounds content by year",
  "icons": {
    "48": "icons/newgrounds-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.newgrounds.com/*"
      ],
      "js": [
        "yeargrounds.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{eedbc32c-b2e2-40d3-b96b-c699e50dc032}"
    }
  }
}