Examine source code of Zombie Buster

{
  "manifest_version": 2,
  "name": "Zombie Buster",
  "version": "1.0",
  "description": "Zombie Buster is a crazy zombie shooter in which you have a bomb-gun you’re not afraid to use",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": {
      "48": "images/icon.png"
    },
    "default_popup": "popup.html",
    "default_title": "Zombie Buster"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{920fe4ca-6802-4e77-b3f8-0c753a2ffd29}"
    }
  }
}