In the Google Play store you'll find “In-App Purchases” written towards the top of the app details screen but in this case it will appear underneath the install button. If you’d like to find out more about the in-app purchases, tap the description and scroll to the bottom. Android shows you a price range for In-App purchases but does not detail precisely what the items are, to find out you will need to actually install the app.
How To restrict In-App Purchases
On Android, it isn’t possible to turn off in-app purchases altogether. However, you can set up your phone so that a password is required before every purchase. To do this, open Google Play then go to Settings and scroll down to ‘Require authentication for purchases’. Tap on this and set it to require authentication ‘for all purchases through Google Play on this device’.