If you have kids, chances are they've gotten into your phone to play games. Since most of our phones aren't exactly set up for children, it's easy for them to get into things they shouldn't. This is why it may be a good idea to set them up with a device specifically for them.
An Android phone is probably the best option because they're highly customizable and very inexpensive compared to other devices aimed at children. The Samsung Galaxy Rush is a good example of a phone that's under $100, runs Android 4.0, and has a front-facing camera.