Examine source code of Navtool

{
  "manifest_version": 2,
  "name": "Navtool",
  "version": "1.2resigned1",
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bdfcd0e2-fff3-4250-9c0d-ca9d9d4d061b}"
    }
  }
}