Notifications

When the app messages you, and how to change it.

Each one turns on or off on its own, on Profile → Notifications.

NotificationWhen
Friend RequestsSomeone adds you.
Game InvitesA friend invites you to play.
Your TurnIt's your turn in a match.
RemindersA match has waited on you for a day or more, or you haven't played in a while.
SupportYou receive a response from support.
Modes & VotingNew modes or community votes.
Profile → Notifications
Profile → Notifications

To turn them all off, use the iPhone's Settings → Notifications → Spades & Clubs.