Are you having trouble with your children spending money through iTunes on your iPhone / iPad by buying games and then purchasing the in-app add ons to complete or enhance the game ?

First make sure you do not tell them your iTunes password.

Next you can set restrictions for In-App purchases

First go into Settings and General

Then scroll down to Restrictions and press on Enable Restrictions 

Then put in a 4 digit password ( make sure you remember this !!!!!)

Then turn on In-App Purchases

Then change the Require Password to Immediately