How do I create chocolate 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!