Edueto is a free service that allows teachers to create their own online activities for students. Teachers can create exercises such as quizzes, matching, writing, sorting, equations, sequences and more and assign them to their students to complete. Student progress is tracked. There are also exercises created by other teachers that you can use and even edit.
It's easy to use and can be a great way to do formative assessment with your students using different formats.
Thanks to Larry Ferlazzo for discovering this. Check out his blog here: http://larryferlazzo.edublogs.org/
Online Assessment Resources
Online Assignments Resources