1. You will see a red square and a red circle on the screen.

2. Place and hold your finger on the square.

3. After a random delay, the circle will turn green.

4. As quickly as possible, lift your finger and tap the green circle.

5. Your reaction time is measured from when the circle turns green to when you tap it.

• Do not lift your finger from the square before the circle turns green — that counts as "too early".

• The square and circle will swap positions each round to test reactions from different angles.

• There are 5 rounds in total.