Examine source code of TabTime Traveler

{
  "manifest_version": 2,
  "name": "TabTime Traveler",
  "version": "1.0",
  "description": "Navigate through the history of closed tabs and windows",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "tabs",
    "sessions",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "TabTime Traveler",
    "default_popup": "popup/popup.html"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "commands": {
    "reopen-last-tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+T"
      },
      "description": "Reopen last closed tab"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6d79049b-d13a-41e3-b55a-b9703f230cce}"
    }
  }
}