A super nice member!
This free tool provides users (up to 10 at a time) with a shared design or problem solving space that can be saved for future reference. It also has an integrated chat feature and so supports collaborative work long distance as well. You can draw, include text and images, and add shapes to your whiteboard. I can see this tool being very useful for small groups of students or adults collaborating on a design challenge, or working on the flow of a computer program or game design or even a presentation. It is very easy to use.
I use Screencast-o-matic to support my flipped learning instruction in information literacy and research skills by creating video clips that demonstrate research skills, such as searching databases, creating citations/Works Cited pages using NoodleTools, evaluating web pages, etc. It is easy to use and to upload created mp4 files to any video storage site. Created videos can be viewed in most browsers with out difficulties.