What are Tokens?
Tokens are basically the currency of the game. Whenever you’re going to use one of the power-ups, you’ll spend tokens. The amount may vary depending on the power-up you’ll use.
The number of tokens you have can be checked by looking at the counter located in the upper right side of the screen. Taping on the counter will redirect you to the game’s store, where you’ll be able to purchase more tokens.
You can learn more about tokens here.