Examine source code of Domain Goalie

{
  "manifest_version": 2,
  "version": "1.2.1",
  "name": "Domain Goalie",
  "description": "Defending your wallet from impulsive domain purchases.",
  "icons": {
    "16": "img/Icon-16.png",
    "32": "img/Icon-32.png",
    "48": "img/Icon-48.png",
    "128": "img/Icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.godaddy.com/*",
        "*://*.namecheap.com/*",
        "*://*.porkbun.com/*",
        "*://domains.google.com/*",
        "*://*.sav.com/*",
        "*://*.dynadot.com/*"
      ],
      "js": [
        "main.js"
      ],
      "css": [
        "main.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{575e06e2-c77f-4540-bf6a-5cdc8898bd2b}"
    }
  }
}