Tap here and start typing.
For grown-ups
Letters is for children who do not read yet: one letter at a time, find it on the keyboard. Words is for readers. No clock takes the timer away entirely, so a child can take as long as they like and Iggy still finishes the race.
A wrong key does not end anything. The word simply starts over, which is what Aaron asked for, and Iggy waits. Winning the race once earns a coloring page, and three wins earns another. Nothing is sent anywhere.