There are many sites that provide a digital corkboard or wall. Here is a new one for lower elementary students- Primary Wall. You don’t need an account- just create a wall, add a post, and then share the link (in edmodo would be a good choice) with your students. You could use it to check for understand, a quick poll, or for homework help. I’ve made a sample (the screen shot is here) free feel to click here to add your comment.