Be it this 'Popup Window' or the other similar 'Popup' extension, both face an issue when merging back to a tab and only 1 tab is opened, in particular userChromeJS scripts fail after Merge.
Hence, an option to prevent the extension from running when only 1 tab is opened would be welcomed.

Works well with some issues:

- Maximize button on pop-up window is disabled/greyed out--pop-up windows cannot be maximized with the maximize button
- would be nice if the pop-up windows was the same size as the window it was "popping up" from, rather than a pre-determined size

That's useful for borderless need. I open several webpage to look borderless documentation. It's Very good!!

add "search text in pop-up window"

please please please please please please please please please please please please please please pretty please

Nice extension. Is it possible to implement alt + click, left + right click or something similar for activation?

It just works

Great extension...must have!

The extension used to hide the mac title bar on the standalone windows, but this has recently stopped working. Any ideas why?

Não faz nada de útil. Cria uma janela que não pode ser maximizada. Qualquer outro navegador faz melhor que isso.

Great add-on! Is there a way to customize the title of the new window? It currently starts with the URL - {title}

I use the WindowTitler add-on (https://addons.mozilla.org/en-US/firefox/addon/window-titler) to add a prefix to my Firefox windows, but the keyboard shortcut to bring up that extension doesn't work in these "popup" windows. Having a way to access that extension would be a workable way to (manually) fix the titlebar.