Examine source code of Tab Group Saver

{
  "manifest_version": 2,
  "name": "Tab Group Saver",
  "version": "1.0",
  "description": "Save and restore groups of tabs easily.",
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Tab Group Saver"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fb3e9cd8-5e01-4045-a052-a0bc6fee712f}"
    }
  }
}