Examine source code of Inspector

{
  "manifest_version": 2,
  "name": "Inspector",
  "version": "1.5",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "search.svg",
    "48": "search.svg",
    "128": "search.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a93f362b-4f36-49a6-850b-867aaa420434}"
    }
  }
}