Examine source code of Winterfox

{
  "manifest_version": 2,
  "name": "Winterfox",
  "version": "1.1",
  "description": "Add some winterly mood to your web browsing!",
  "icons": {
    "48": "icons/winterfox-48.png"
  },
  "background": {
    "scripts": [
      "global-state.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/winterfox-48.png",
    "default_popup": "popup/popup.html",
    "default_title": "Winterfox"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "particles.js",
        "winterfox.js"
      ]
    }
  ],
  "permissions": [
    "activeTab"
  ]
}