Examine source code of HsReplayWheel

{
  "manifest_version": 2,
  "name": "HsReplayWheel",
  "version": "1.0",
  "description": "Adds a wheel to hsreaply",
  "icons": {
    "48": "icon48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://hsreplay.net/meta*"
      ],
      "js": [
        "roulette.js"
      ],
      "css": [
        "roulette.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d2c211bf-4f8e-4774-9b35-086689c836bf}"
    }
  }
}