I completely agree with Gabe Weatherhead’s views on apps made for kids in The Value Of App Reviews:

My number one reason to give a bad rating and review is when an app made for kids has both up-sell and review requests plastered all over the screen. They are trying to prey on small children tapping anything that pops on the screen. If you make a kids app, do not put links to your other apps in the game. Put them in the preferences. Put them in the app description. Hell, put them in some kind of app documentation. But when they are in the game, you are telling me that you’re shady and unscrupulous and I can’t trust your app.

This is a dark pattern, and I simply delete the app if I come across this kind of design. For some better patterns to follow when designing apps for kids, see Luke Wroblewski’s Touch-based App Design for Toddlers.