Examine source code of Karciarz

{
  "manifest_version": 2,
  "name": "Karciarz",
  "version": "1.9.1",
  "description": "Synchronizuje karty",
  "browser_action": {
    "default_title": "Karciarz",
    "default_popup": "popup/popup.html",
    "default_icon": "icon32.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "webNavigation",
    "storage",
    "alarms"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{dd12f0bb-882b-48de-9f05-c1a2013803a3}"
    }
  }
}