Examine source code of ICEfinder

{
  "manifest_version": 2,
  "name": "ICEfinder",
  "version": "2.0.1",
  "description": "Finds the type of ICE train and displays it in the results when searching on the DB website",
  "icons": {
    "48": "icons/icefinder-48.png",
    "96": "icons/icefinder-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.bahn.de/buchung/fahrplan/suche*"
      ],
      "js": [
        "icefinder.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2f41f9f2-ac40-46eb-a77c-30f56830ab5e}"
    }
  }
}