Examine source code of Socket.IO Test Client

{
  "name": "Socket.IO Test Client",
  "description": "Socket.IO Client Development Tool",
  "manifest_version": 2,
  "version": "1.1.0",
  "icons": {
    "16": "images/socketio16.png",
    "48": "images/socketio48.png",
    "128": "images/socketio.png"
  },
  "browser_action": {
    "default_title": "Click to start!"
  },
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{77713be1-7fac-4c49-9e5b-81c894a061f9}"
    }
  }
}