The GamingStein is a small piece of selenite which is mounted to a little wooden base. In this base, there are five WS2812B LEDs and an ESP8266, as well as an AMS1117 voltage regulator. The colours of the LEDs can be adjusted using the Telegram bot which was created using the BotFather.
Just flash the sketch to your ESP8266 DevBoard and give it a try.
By the way: The correct pronunciation of GamingStein is [ˈɡɛɪ̯mɪŋ|ʃtaɪ̯n].