My Take
I think it is a great tool to help students pick out main ideas and make notes on the things they highlight. The one thing that can be frustrating is that if one student highlights something another student can not highlight over top of what another student said. I think the document gets messy with all the highlighting that occurs. I overall really enjoy using this app.
How I Use It
I would use this in my teaching to help students pick out the main points and maybe facts they think are important. I think it is a great tool for collaboration.