The main menu contains screens with all your games, ranking and achievements. The screens “your turn” and “their turn” show the games you’re currently playing. The “finished games” screen shows the game results. The “your ranking” screen shows your overall ranking for every type of game you’ve played. The “achievements” screen shows your (un)locked achievements.
The plus sign in the bottom opens “new game” and the small cogwheel in the bottom menu opens the settings page. Pressing the “…” gives access to the “developer blog” and the “marketplace”.