I had my students do Edmodo every week for homework. They have polls, questions that were due every week. They liked doing homework on Edmodo and asked for it every week. It was a great way to intergrate technology in the classroom. Here's my sample:
Edmodo Quiz and poll
I hadn't use Wallwisher but I find it very useful. I can put messages for the kids and keep them up in the classroom before class starts and while they work.