Examine source code of Bookmark Open Tabs

{
  "manifest_version": 2,
  "author": "henryspeakerdev+firefox-bookmarks@gmail.com",
  "name": "Bookmark Open Tabs",
  "description": "Bookmark all or some open tabs. Choose where the bookmarks are saved. Open previously saved bookmarks in new windows.",
  "version": "0.1.0",
  "icons": {
    "16": "icons/bookmark-16.png",
    "32": "icons/bookmark-32.png",
    "48": "icons/bookmark-48.png",
    "128": "icons/bookmark-128.png"
  },
  "browser_action": {
    "default_icon": "icons/bookmark-128.png",
    "default_popup": "pages/menu.html",
    "default_title": "Bookmark Open Tabs"
  },
  "permissions": [
    "bookmarks",
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5ed2209e-e137-45a6-b92a-0ca7377699ae}"
    }
  }
}