Examine source code of Repeat after Forvo

{
  "manifest_version": 2,
  "name": "Repeat after Forvo",
  "version": "1.3",
  "description": "Improve your pronunciation. Repeat after Forvo.",
  "icons": {
    "64": "icons/icon-64.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://forvo.com/word/*",
        "*://*.forvo.com/word/*"
      ],
      "js": [
        "raf.js"
      ]
    }
  ]
}