How to use Android 4.3’s ‘Restricted Profile’ feature
The ability to add a second user profile was added to tablets in Android 4.2, and it's gained even more granular functionality in Android 4.3 with the addition of "restricted profiles." In a nutshell, this lets you choose which applications that restricted user can use.
It's not quite a full-functioned kids mode, and there still are a couple things to watch out for. But for basic account compartmentalization, it works pretty well.