Touch on an empty field in order to create a new element (you can see the upcoming tile on the right side)

Perks

Bombs

Drag'n'Drop the bomb on an empty spot and double-tap/click on it. Then the countdown will start. Once the countdown is running, you cannot change the bomb position anymore.

Jokers

Drag'n'Drop the joker on an existing tile, then the next upcoming tile will be set to the selected one.