You can buy the Double Spinning Tops booster before the start of a level or get it as a reward. It especially comes in handy on hard levels with level goals that are hard to reach.

Tap the icon in the window that appears before the start of a level to activate the booster. You don't see it on the field, but you do get twice as many Spinning Tops in the level when you activate one.

Activate one Spinning Top and get two of them!