Pokémon Shuffle/Gameplay

Hearts
Hearts are used to play stages. One heart recharges every 30 minutes up to a cap of 5 hearts. You can exceed the 5 heart limit by exchanging jewels for hearts, but they stop recharging until you go below the 5 heart limit.

Coins
Coins are used to purchase items at the start of a stage or great balls when attempting to capture a Pokémon.

Jewels
Jewels are in-game currency that can be bought with funds from the Nintendo eShop. They can be exchanged for hearts or coins.