Boosters give you special abilities to board passengers onto the busses. You can find them at the bottom of the screen while playing a level. To use a booster simply click on it to activate it.

↩️ Undo allows you to reverse the last move you've made.

⬜ Extra Tiles provides you an extra three tiles, allowing you to send more passengers to clear the board.

🖌️ Color Picker picks a passenger in the current bus color from anywhere on the board and puts them on the bus.