How do I create Choco Boosters, and what do they do?

In Sugar Blast, there are three boosters you can create: Line Choco, Cross Choco, and Choco Bomb. To create a Line Choco, tap a matching set of 4 or more candies of the same color. The more candies you combine, the bigger the booster will be. 

Power up even further by combining boosters! Combining two Line Chocos will create a Cross Choco that is the same size as the largest Line Choco. Similarly, combining two Cross Chocos will create a Bomb Choco. Using these boosters is a great way to blast a large amount of candies at once!