Fun Google tip for the day - I don't know if there are any parental controls for the Google Play Store or if that is something that can be blocked by your Nook settings but for people trying out the new Play Store on their Nooks, you might want to be aware that your kids could accidently be faced with some 'inappropriate for kids' apps by just clicking on the top new free apps tab. That was in the Libraries & Demo category for anyone who wants to know.
If you tap on your settings(3 dots in the right corner) of your google appstore app, you'll see settings. Tapping on that brings up User Controls. Tapping on that, brings up Content Filtering.