In terms of smoothness, the application is perfect. However, there are a few issues that need to be resolved to get five stars: first off, many people, when a loss is inevitable, leave the game and force the game to either be adjourned or their turn be cast into infinity. The only way to circumnavigate this is to leave the app and reenter. To my knowledge, this forces you to take a loss for the game instead of the deserved win. The second issue, which is unbelievably annoying, is that mid-game, the app store randomly opens. Fix these two issues and Ill be five stars.
:::::Update:::::
The app will not let me sign in to play online, and this is the only mode I use....very annoying. Connection is good, game and iOS are most recent on an iPhone 6s....should be working