simple, effective

This works well but it's a bit annoying that it requires interaction.

This extension is perfect unless combined with Popup window, which leaves you with no way to click the toolbar icon. If you added a potentially optional right click context menu option this would be a 5 star hands down.

Playing with the two together a little more it's possible to merge the window and activate yours. But as soon as I popup the window again there is a lot of scrolling stutter. This problem goes away if I merge the window again and disable Hide Fixed Elements.

Still think it's awesome

It works really well on the websites where I usually need it. It would be great if the addon could remember certain sites, and also being able to select certains parts of the web. Nice Work!

Works great. I've been using a bookmarklet for the same purpose, but this gives me a single button in the toolbar.

Docked one star because it needs:
* keyboard shortcut
* automatic application on page load

But as of June 2018, there are no competing Add-Ons in Firefox that have either of those features.

Great start. Works well with Medium, but messes with Twitter's head! :)
Will try it on other sites as and when they annoy me! :)