Examine source code of Fun cave. .

{
  "theme": {
    "images": {
      "theme_frame": "0701--koiro-l4-kaiga--sasikae-betu.jpg"
    },
    "colors": {
      "frame": "#ced9f0",
      "tab_background_text": "#ed1d1d"
    }
  },
  "version": "2.0",
  "name": "Fun cave. .",
  "manifest_version": 2,
  "description": "たのしい洞窟\n\n\n\n0423--koiro-l4-kaigaputuputu-●↓\n0701--koiro-l4-kaiga--sasikae-betu"
}