The app is free to download and play but additional maps, characters and items are available to purchase from the app as follows:

Add-on character x 1: $0.99
Add-on map x 1: $3.99
Golden hourglasses (consumable item; pack of 3): $0.99
Golden hourglasses; pack of 8: $1.99
Golden hourglasses; pack of 20: $2.99