As I've said before, I am a big fan of IssacPhysics.org and I really feel that its not just a website, but a whole concept whose time may just have arrived.
This is a resource that allows you to link whole classes together online, to set the class pre-designed questions and then monitor their progress, allowing you to see who has engaged with the exercise or not. And who has struggled.
Like any big website, it can be a little intimidating to get started with it. Isaac themselves have a number of videos and guides to their site which are great. The video I'm linking to here is limited to how I interact with the site and how I got started. I think it may have the advantage of being put together with use in an Irish school in mind.
Basically, the steps are:
create an a/c
email Isaac and ask to be registered with them as a teacher
create a 'group', generating a link that you can email to students
select questions (boards) that will work for your students, and save them to 'MyBoards'
assign the work to your group
I should stress that I'm not linked to Isaac in any way. I'm just a fan. This resource should be viewed in that light.