Examine source code of MapsNail

{
  "manifest_version": 2,
  "name": "MapsNail",
  "version": "1.0",
  "description": "Makes Google Maps Thumbnails from Google searches clickable again.",
  "icons": {
    "48": "logo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.google.com/search*"
      ],
      "js": [
        "mapsnail.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e2a9bb3-1bcf-477b-9828-89d53cdf5b41}"
    }
  }
}