There are two types of items: boosters that can be used before gameplay and items that can be used during gameplay.

• The hourglass and shooting star can be checked before gameplay. The number of items you own is displayed at the bottom right of each item in the pre-start popup menu. 
•  The UFO, Pudding, Plane, and Snowman can be checked during gameplay. The number of items you own is displayed at the top right of each item at the bottom of the gameplay screen.