Examine source code of Immobilien.net

{
  "theme": {
    "images": {
      "theme_frame": "personas-eres.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#000"
    }
  },
  "version": "2.0",
  "name": "Immobilien.net",
  "manifest_version": 2,
  "description": "<a href=\"https://outgoing.prod.mozaws.net/v1/b71d1d6f66edfe901c2183fa09f3cc6ac2d5bc5d2e7806188fa1e6654e8ff80b/http%3A//Immobilien.net\" rel=\"nofollow\">Immobilien.net</a>"
}