LeechBlock NG
Website Blocking Tool

Some parents have found that the Chrome Browser extension, LeechBlock offers them some control over what younger students can access on their Chromebooks. Parents can block student access to distracting or unproductive websites. 

LeechBlock allows parents to create a password protected list of sites that are blocked from student access and/or set a schedule for when these sites are blocked (ie. school day).LeechBlock will also block sub domains.

LeechBlock is a Chrome extension that is installed on all student Chrome accounts. It can launched and configured from the extensions