Examine source code of Defrost

{
  "manifest_version": 2,
  "name": "Defrost",
  "version": "1.4",
  "description": "Remove parts of a web page that freeze up the user experience",
  "icons": {
    "16": "assests/icon.svg",
    "48": "assests/icon.svg",
    "128": "assests/icon.svg"
  },
  "page_action": {
    "default_title": "Defrost this page",
    "default_icon": "assests/page-action-icon.svg",
    "show_matches": [
      "*://*.instagram.com/*",
      "*://*.facebook.com/*",
      "*://*.pinterest.com/*",
      "*://*.pinterest.de/*",
      "*://*.pinterest.fr/*",
      "*://*.pinterest.co.uk/*",
      "*://*.pinterest.nl/*",
      "*://*.ftm.nl/*"
    ]
  },
  "background": {
    "scripts": [
      "domains.js",
      "background.js"
    ]
  },
  "permissions": [
    "activeTab"
  ]
}