It is important for students especially in the younger grade to take breaks to get some of their energy out to get them back in focus. Go Noodle is an excellent website with various short dance breaks to help accomplish this.
This is a great tool for extra reading and math practice which can be monitored by teacher as well as adapted to student needs.
This website is great for creating online quizzes for students which can either be played with the teacher leading it or students on their own. All results are saved and kept for teacher to reference and grade.