Had a chance to play the multiplayer last night, and had a few issues. I was on 4G at the time, and this is a SGS4. The other player was playing in Fry's usual spot.
On the first hand of one of our games, the word "Passed" never disappeared from my partner's dominoes, and it never revealed the trump to me (wasn't Follow Me).
That only happened once, but the "passed" staying on screen happened a few times.
Another time, midhand, the bidding wheel popped up. We were three or four dominoes in, and the win/set conditions hadn't been met. I could still play my dominoes, but, and this is the sleep deprivation showing, I believe the game ended prematurely and a new wheel popped up. The first one had a minimum bid of 32, the new one 30.
Connection was spotty, so I couldn't tell what was lag on the software's part vs wonky cell signal.
Enjoying where the app is headed, though. Was well worth the money. It's hard to find people to play in VA, so this is a good fix.