I'm exploring how to check variables for a first time vs. return game.  It's great to know that all variables in Voice Apps are persistent.. so any change made will be remembered for your next time.   So for starters I'll make sure it's Welcome vs. Welcome back.. but we could do more things like saving the person's name for the future as well.

I found this tutorial on how to do vary your greetings based on visit.  not as deep as using real variables but it makes this one part super easy to do for any skill with voice apps.  easy to implement.