Cacoo
https://cacoo.com
Cacoo is an online mind-map that can be used in collaboration with colleagues and other 'minds'. An idea is started by one person and others can add to it, creating a visual mind map.
I think this would be effective to use in education. If all the children in a classroom were registered, it would be a large help for group projects or assignments. Group members can add to their fellow classmate's ideas and therefore help eachother learn.
I think that children who do not like working individually would enjoy this website. As well, children who may have issue with group work that is focussed on being verbal may find that it is easier to express themselves through text, on a mindmap. Visual learners would also benefit from the mind map part of it.
There is no required age for this and I believe it could be used in any age grouping.
