Simoleons are the main currency used in The Sims FreePlay and other Sims games. You Sims can earn money by cooking, working, their cat or dog will find will find it, gardening or collecting revenue from the town map. You can use them to buy furniture, houses, cars and shops. You can also buy Simeleon packs from the Online Store. Simeleons are the official currency of SimNation which is used in all games in The Sims Series.
If players leave their game for a week or longer, when they return, they will receive free Simoleons (amount varies).