Examine source code of Tab Gallery

{
  "manifest_version": 3,
  "name": "Tab Gallery",
  "version": "1.0.1",
  "description": "Show all tabs in the current window in a beautiful, searchable grid.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "tabgallery@rifat.com"
    }
  }
}