Examine source code of Quick Page Saver

{
  "manifest_version": 2,
  "name": "Quick Page Saver",
  "version": "1.0",
  "description": "Quickly save the current page's HTML source to your computer.",
  "permissions": [
    "activeTab",
    "downloads"
  ],
  "browser_action": {
    "default_title": "Quick Page Saver",
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icon.png",
    "128": "icon.png"
  },
  "applications": {
    "gecko": {
      "id": "quickpagesaver@example.com",
      "strict_min_version": "60.0"
    }
  }
}