Examine source code of Queue

{
  "name": "Queue",
  "description": "A WebExtension for queueing links.",
  "version": "0.3.2",
  "permissions": [
    "contextMenus",
    "storage"
  ],
  "options_ui": {
    "page": "options/index.html",
    "open_in_tab": true
  },
  "icons": {
    "128": "assets/queue.png"
  },
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "128": "assets/queue.png"
    }
  },
  "background": {
    "scripts": [
      "background-scripts/initialize.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "{c3560e6b-00e5-4ab3-b89e-8a54ee5b2c9f}"
    }
  }
}