Examine source code of PrehrajtoWatch

{
  "manifest_version": 2,
  "name": "PrehrajtoWatch",
  "version": "4.0.2",
  "content_scripts": [
    {
      "matches": [
        "*://*.prehraj.to/*",
        "*://*.prehrajto.cz/*"
      ],
      "js": [
        "main.js"
      ]
    }
  ],
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{510385eb-644b-494a-870b-c4fb4576aa2d}"
    }
  }
}