Examine source code of Sizzy

{
  "manifest_version": 2,
  "name": "Sizzy",
  "version": "1.0",
  "description": "The responsive design browser (sizzy.co)",
  "icons": {
    "48": "icons/sizzy-48.png",
    "96": "icons/sizzy-96.png"
  },
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/sizzy-96.png",
    "default_title": "Sizzy"
  },
  "background": {
    "scripts": [
      "sizzy.js"
    ]
  }
}