Each booster does its own specific thing:

Time boosterallows the generators on the Merge field to work without recharging. Just tap to activate. In temporary expeditions, drag it onto a generator to speed up its charging.

Scissors booster   can divide an item into two lower-level items;
 
Hypercube booster   increases the level of an item.

Surprise booster gives you a chance to earn extra reward when completing a merge order! Finish the order marked with a treasure chest within the set time and claim your bonus.

Lucky bag let you сhoose one of three random merge items to help you complete orders! Take it from storage and open with a tap.

Keep in mind: you can store any booster in your backpack, but once the Accelerator is activated, it can’t be placed back!