Each letter is a full lesson of about 25 taps: meet it, tap its sound, meet its little letter, three words, pop bubbles, find it, match big and little, pick the picture that starts with its sound, trace it, say it, then four questions with no help. A letter counts as known only when your child gets all four no-help questions right on three different days. English and Spanish are scored separately. Known letters get checked again after 14 days.