For those of you who are technology oriented, you may want to check out the free "Tech & Learning" publication. It has a lot of good content in it and covers everything from apps to hardware to policy, etc. If you want to check it out, you can use this link to subscribe to the printed publication for free.
I had a teacher ask me if there was a way to hide or remove students who are no longer in your class. The answer is maybe. It depends on if they are officially dropped from your class and appearing as red in your roster and gradebook. If not, then no, you cannot remove them until they have been unenrolled from the class. If the student is showing up as red in your gradebook though, you can hide them so you don't have to worry about them. Here is a screenshot to help you do it: