Floating Doc Controls

It would be great for more lengthy documents to have floating controls. For example, I have a lot of different charts and data views on one page, and a button to toggle a couple different variables in the data and see how the charts change. Right now, I have to duplicate the button throughout the page or put it at the top and scroll up everytime I want to use it.

It would be very useful to have a little sidebar or floating box that I could put some buttons like this in and access anywhere on the doc.