The Hammer is a booster available only when you’re playing a level. You can find its icon on the level goals bar next to the Torpedo.

The Hammer booster removes one piece or one layer of any obstacle (e.g., one chain out of two) without using a move.

Follow these steps if you want to use the booster:
1. Tap its icon.
2. Tap the tile that you want to clear.

The Hammer comes in really handy when you need to remove a piece that is particularly hard to reach, or when you don't have enough moves left to complete the level goals.

You can purchase the Hammer booster when you’re playing a level.