MobyMax is an all-inclusive K-8 curricular site that focuses filling in the missing gaps in a students education. The students start with an adaptive placement assessment which then places the student at their grade level proficiency based on the Common Core Standards in the areas where gaps were when the student took the assessment. MobyMax provides a great visual for both teacher and student data tracking, progress monitoring, and setting goals.
Students are assigned automatically based on these CCSS and skill gaps. All subjects can be assigned, in addition to many other tools for the classroom use. Tools such as messenger, classroom wall, clickers, vibes which focuses on behavior, contests, badges, and games. From what I see and have used, MobyMax has is it all.
As with other sites, you have automatic sign in, a unique school code for students to login, and full control of what your students see, use, and do on the site. I found MobyMax engaging, easy to use, motivating, and intuitive for both the teacher and student. Best part is that it has a free version, check out MobyMax and let me know what you think!