Power-ups appear on the game field once you match four or more pieces. These power-ups are available in the game right now:
Rockets potions clear all tiles in a row or a column (depending on which direction they're pointed in). You can get them by matching four pieces in a line.
Bomb potions are activated by a double tap and remove a significant number of pieces. You can get them by matching five or six pieces in an L or T formation.
Frogs remove two random pieces on the field: they tend to hit locked elements or level goals first. You can get them by matching four pieces of the same type in a square.
A Rainbow potion removes all the pieces of the same type from the field. You can get them by matching five pieces in a line.