Examine source code of Save Tabs to JSON

{
  "manifest_version": 2,
  "name": "Save Tabs to JSON",
  "version": "8",
  "permissions": [
    "tabs",
    "downloads"
  ],
  "background": {
    "scripts": [
      "background.js",
      "file-selector.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon48.png"
    }
  },
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    "file-selector.html",
    "file-selector.js"
  ],
  "applications": {
    "gecko": {
      "id": "save-tabs@img.com"
    }
  }
}