Lollipop Hammer is one of the boosters in Candy Crush Jelly Saga that is unlocked in level 7. It is activated in-game by clicking the corresponding button. Clicking the same button again deactivates it.
It is a booster that the player can use to remove a candy or a blocker without using a move. You can smash once into any candy or most blockers. For example if a lollipop hammer is used on a multilayered cupcake, it will remove one layer.