Once you match 4 or more pieces, a Blaster will be generated on your board.
Boosters work the same way Blasters work, only with the difference that you do not lose a move when you use one. Boosters in the game come in two types: pre-game and in-game. Pre-game boosters are Missiles, Bomb and Double Missiles, and Disco Ball. In-game boosters are plain mallets and rainbow mallets. A plain mallet removes an obstacle from the applied cell but by using a rainbow mallet you can remove all pieces that match the colour of the piece you hit. Do not worry if you have run out of your boosters: you can always buy one before you start a level!