Raz-Kids is a site that I found out about from my son's KDG class. This is a great site for interactive eBooks that kids can read along w/ at their own pace. Also, at the end of each book they can either take an online quiz or print out worksheets that go along w/ it. There is a paid teacher portal where they can get a class account.
I highly recommend checking out Raz-Kids by clicking here!!!