Examine source code of switch2

{
  "manifest_version": 2,
  "name": "switch2",
  "version": "1.0",
  "description": "Auto switch to URL",
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d88db161-0608-45ab-ad6b-145f76acd614}"
    }
  }
}