Examine source code of Twitch Claim Box

{
  "manifest_version": 2,
  "name": "Twitch Claim Box",
  "version": "1.1",
  "description": "Récpère les récompenses des streams Twitch.",
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "paulos.ruben@gmail.com"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitch.tv/*"
      ],
      "js": [
        "app.js"
      ]
    }
  ]
}