It is very easy to get too busy to make sure that the kids are studying. When you are consentrating on so many things, the kids get lost in the shuffle. Khan Academy is a great website that allows you to create a lesson plan that can be tracked.
I have found it very useful . My only problems are two things: One you have to have a Google or Facebook account to join. This was not a problem for my older kids but an issue for the seven year-olds. My other issue is that the information tracking does not show up in the mobile application. These small issues are small and I am sure they will be addressed with later updates to the site.
I highly recommend that this site as it will give you a way to have study time over and above their school work.
Check out this video where the one and only Bill Gates co-signs this site: