Examine source code of MrBiller.com

{
  "manifest_version": 2,
  "name": "MrBiller",
  "description": "MrBiller Login for firefox",
  "version": "1.0",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": "b96.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "b16.png",
    "32": "b32.png",
    "96": "b96.png",
    "128": "b128.png"
  },
  "web_accessible_resources": [
    "popup.html",
    "jquery.js",
    "popup.js"
  ],
  "background": {
    "scripts": [
      "jquery.js",
      "background.js"
    ]
  }
}