A lot or a little?
Parents need to know that Tap Zoo is a free app that lets kids build and customize their own virtual zoo, but that the game is designed so that kids have to wait a long time between purchasing animals or buildings for their zoo. Early in the game, you will only earn a few hundred coins from your zoo, but anything you want to buy will cost far more than that (example: a hedgehog is 16,000 coins). If you don't want to wait, you will need to spend real money to buy extra coins. Many animals and items can't even be bought with coins -- they need to be purchased with "stars," which are rarely ever earned within the game and almost certainly need to be purchased with real money.