This is great feedback. Right now I'm trying to finish our first book for http://non.io (site isn't complete yet, but it will still give you an idea of the core concept), and one of my considerations was ensuring that the app was child friendly. At the end of the day, there will be options and components that are for parents only. Ensuring that a.) they're still prominent enough for parents to see at some point, and b.) that they're out of reach of children is a difficult balancing act. Does anyone know of or have any suggestions of apps who have done this correctly? I only have two components that are for parents - a donation form and an email signup form on the last page. Right now they're disabled until you select a checkbox that says "I'm an adult". Would love to get more feedback on this though.