This lets you launch a completely different user interface, with only the apps you've chosen as safe for your kids. (pocket-lint.com)
It's a very good app for customizing your Windows Phone and a new version was recently released, Wiztiles Pro, that brings a slightly different user interface into play as well as these changes / features. (windowscentral.com)
There are many different user interfaces for Android. (intomobile.com)