This was a huge chapter, filled with tons of Phoenix real-time application building! We've covered adding actual voting functionality and ES2015 syntax, written a great deal of non-Elixir code, and dove into arguably one of the coolest portions of built-in functionality on the Phoenix side!
We've done a lot of the hardest pieces of work, as well; we've covered all of our new work with tests as part of our development lifecycle and written JavaScript code to swap out functionality depending on what level of features our browsers support!