The home screen shows Play today's challenge. Every player gets the same sequence of objects on the same day. You have one try: the attempt counts as soon as you start.
Twice the XP, and a streak
The Daily Challenge gives twice the usual XP and extra coins. Each day you play it adds one to your streak, shown with a flame at the top of the home screen. When today's game is done, the card says when the next one comes back.
Daily missions
Under the challenge, three missions change every day, such as playing a number of games or reaching a score. Each pays coins when you complete it.