UI for the thumb. [Pixels attached]

So for Wildcard we are exploring the possibility for users to join multiple decks (a group of people based on location). After joining a Deck it will show up next to the FAB (floating action button) on the bottom right = thumb zone of your device.

By placing it relative to the 'adding' action it gives users direct feedback (adding) and helps them look at their joined decks directly in the UI - no scroll/swipe needed.