On the app information page, there’ll be “Offers In-App Purchases” under the name of the app developer. If you see this, scroll right down to the bottom and tap on “In-App Purchases”. Here, you’ll be able to see the type of purchases available in the game and you can then decide if you want to give it a try.
How To restrict In-App Purchases
There are two settings to help protect you from unwanted purchase on iOS. The first thing you can do is set up your device to always require a password. You can do this through Settings > iTunes & App Store > Password Settings and selecting the ‘Always Require’ (pictured below left)
For extra security, you can also turn off in-app purchases entirely at the system level. To do this, go to Settings > General > Restrictions and change the In-App Purchases option to be off (pictured below right).