Examine source code of Tetrys

{
  "browser_action": {
    "default_icon": "assets/icon.png",
    "default_popup": "index.html"
  },
  "description": "Tetrys for Firefox with no ads",
  "icons": {
    "256": "assets/icon.png"
  },
  "manifest_version": 2,
  "name": "Tetrys",
  "version": "1.3.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a74a3747-1f76-4a2c-bb9e-deb0117697cf}"
    }
  }
}