Famigo is a service offering reviews of and recommendations of apps for kids to use on Android phones and iPhones. I wrote a review of it earlier this year. Since then Famigo launched a free Android app called Famigo Sandbox.
Famigo Sandbox is an Android app that allows you to create a "kids-only" section on your Android phone. With Famigo Sandbox installed and activated when you hand your phone to your child your child cannot accidentally access your contacts, dial the phone, or access apps that are not in the Famigo Sandbox. Famigo Sandbox also provides you with recommendations for new apps for your child to try.
The two minute video below provides an overview of the Famigo Sandbox Android app.
Applications for Education
I don't know of any teachers who are in the habit of handing their phones to young students. But if you have young children of your own that occasionally use your phone to play an educational game, this app could be for you.