See who is actively on a board at the same time as you

It would be great to have a feature similar to google docs that allows you to see who is working/making edits to a board at the same time.

You can see by digging into the activity log, but an icon that you can quickly view at the top of a board would be really helpful to avoid confusion. It has happened within my team that 2 people are working on a board and accidentally edit each others items at the same time causing confusion.