Straight Ace Learning lets you easily create virtual English and Math classrooms for elementary and middle-school students, and provides curriculum that they say is Common Core-aligned. The content isn’t very flashy, but I could easily see myself offering it to students for reinforcing online work at home.
It’s easy to sign-up, and then they send you registration information a day-or-two later.
They’re working with Quipper School, which has similar multilingual programs in several Asian nations.
I’m adding it to The Best Sites That Students Can Use Independently And Let Teachers Check On Progress.