Seventeen words hide four groups of four, plus one word that belongs to none of them. Pick four cards and tap Submit to lock in a group. You can make four mistakes. Think you've already spotted the odd one out? Pick that single card and tap "Odd one!" for a bonus, but a wrong call costs a pin. Stuck? Each hint reveals the name of a group you haven't found, plus one word that belongs in it. Hints add one to your leaderboard score.