Examine source code of UniqueTabs

{
  "manifest_version": 2,
  "name": "UniqueTab",
  "version": "1.1resigned1",
  "description": "Removes not unique tabs",
  "icons": {
    "48": "icons/tab-remove-48x48.png"
  },
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/tab-remove-32x32.png",
    "default_title": "UniqueTab"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5798c41a-33ac-48a8-80a7-b8dd5a38b188}"
    }
  }
}