Are there any totally free kids games

Unfortunately, most free games are ad supported. The app store is supposed to have a special kids section, there might be some games that better suit your needs there.

You will want to read the reviews and look for in app purchases. Last time I was in the app store looking for something it seemed that every 'free' app had multiple in app purchases, however I was looking for something very specific.

Last I knew you could sort the app store for paid and free apps, so maybe you could look for the kids part and start with the free ones and then read the reviews, see if there are any that are really free.

Suggest you use Restrictions to prohibit in-app purchases on games for kids.

 Cheers, Tom 😉