classworks
We do use classworks, both in the school where I now teach and in the school where I did my Internships (same county)
My Internship school used it as a literacy center and then we also took the students to the Computer lab once a week, divided the students into 2 groups-one group did Math activities while the other did the Language Arts. Where I teach now, I just got it started on my computers, but my plan is to use it during REading for Center (during Small Group) and as a "what to do when you are finished" and as intervention for students who need more practice.
I look forward to seeing other responses---