I'm web developer on mac os and I need a feature that allow's to pin web inspector in separate window always on top of current page. I'm trying to create addon with this feature, never did it before. Researched developer.mozilla.org but can't find any ability to do it. Any suggestions how to do it?
You'll have to use this addon - https://addons.mozilla.org/en-US/firefox/addon/topick/
You can set any hotkey you want. On Windows and Linux it supports toggling "always on top"-ness for all system windows (not just Firefox). On Mac it currently is limited to just Firefox windows, but hopefully soon it will be system wide on Mac as well.