Generation Z (my 10 year old nephew's generation) doesn't get
   decoder rings, but they get secret messages to decode in this
   show - one of the best things to hit kids TV in a long time.
   They have a character named "Bill Cipher" who is a four
   dimensional being that we only see in 2 dimensions in our 3
   dimensional Universe and they have secret messages to decode all
   the time in it. Awesome stuff.
   [1]https://www.youtube.com/watch?v=ZtlX1pujSr4

References

   Visible links
   1. https://www.youtube.com/watch?v=ZtlX1pujSr4