I know that you are working on the AI, but after playing nearly 10-15 games per day, I have some worries. I started playing face up to test my theories. First, it seems that the piece of code that randomizes the dominos during the deal plays favorites to Phillip and Fry. What I mean is that 90%+ of the time, our opponents receive multiple doubles along with 3-4 of a high trump suit whilst Jay and I continue to receive shotty hands. Next, it appears as though the computer opponents know exactly what is in everybody's hand. They will have a couple offs and just happen to continuously throw the off that their opponent has the double of. Even when logically the off shouldn't be thrown, they will throw it "knowing" that their opponent will catch it. I know it's next to impossible for the computer not to know because of the number memory, but it seems way to obvious.
With that said, I know you are working on multiplayer instead of AI at this point but I worry that there won't consistently be enough players for the multiplayer to work. Also, if you have fewer than 4 real players, will it be set up to where an AI player takes one or more positions. If that's the case, I would think the AI should be up to par before multiplayer.
I still think this is an awesome app, but I just wanted to voice concerns. Because we are just communicating in text, it may come off that I'm trying to be an @$$, but I am just legitimately trying to help.