After a certain amount of story progress, you will unlock the Radio Tower. Here you can collect free daily boosters and activate other boosters that increase your rewards for the next few rounds. Depending on the booster, you can earn more coins, get more items, or increase your location rank faster!

The following boosters are available:

Coin Boosters

Binder Boosters

Scene Rank Boosters

XP Boosters

You can access the Radio Tower by tapping on it or on one of the booster icons in the upper-left part of the screen.