Examine source code of Tab notifier

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "tabnotifier@unusoft.it"
    }
  },
  "background": {
    "scripts": [
      "tnHelper.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "js": [
        "tabnot.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "description": "__MSG_extensionDescription__",
  "icons": {
    "16": "icon16.png",
    "48": "icon.png"
  },
  "name": "Tab Notifier",
  "permissions": [
    "tabs",
    "notifications",
    "storage"
  ],
  "version": "3.1.2resigned1",
  "browser_action": {
    "default_icon": {
      "16": "icon16.png",
      "48": "icon.png"
    },
    "default_title": "Tab Notifier",
    "default_popup": "options.html?popup=1",
    "browser_style": false
  },
  "options_ui": {
    "page": "options.html"
  },
  "default_locale": "en"
}