Examine source code of Better Zillow

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Better Zillow",
  "description": "Turn Zillow into a Google Map for finding Real Estate.",
  "version": "0.0.0.1",
  "short_name": "BZ",
  "page_action": {
    "default_icon": {
      "16": "/images/icon-16x16.png",
      "32": "/images/icon-32x32.png",
      "48": "/images/icon-48x48.png",
      "128": "/images/icon-128x128.png"
    }
  },
  "icons": {
    "16": "/images/icon-16x16.png",
    "32": "/images/icon-32x32.png",
    "48": "/images/icon-48x48.png",
    "128": "/images/icon-128x128.png"
  },
  "permissions": [
    "activeTab",
    "https://*.zillow.com/*/*"
  ],
  "content_security_policy": "default-src 'self'",
  "content_scripts": [
    {
      "matches": [
        "https://*.zillow.com/*"
      ],
      "css": [
        "enhanced-styles.css"
      ]
    }
  ]
}