Examine source code of Scratch Pad

{
  "manifest_version": 2,
  "name": "Scratch Pad",
  "version": "2.4",
  "description": "Simple note taking app that you can set as your homepage.",
  "icons": {
    "48": "icons/scratchpad-48.png",
    "96": "icons/scratchpad-96.png"
  },
  "background": {
    "scripts": [
      "scratchpad.js"
    ]
  },
  "web_accessible_resources": [
    "src/index.html"
  ],
  "browser_action": {
    "default_icon": {
      "19": "buttons/scratchpad-19.png",
      "38": "buttons/scratchpad-38.png"
    },
    "default_title": "Scratch Pad"
  },
  "permissions": [
    "tabs"
  ]
}