Does what it says. Finds all files including js, jpg, gif, css, etc.
I had one problem after installing, just like Не работает writes: it opened only empty tabs. After removing a legacy extension, it worked. I don't remember which extension it was, but it was a legacy extension.
So if it doesn't work, you may try disabling legacy extensions.

Genau was ich gesucht habe! Dieses Add-On ist mir eine große Hilfe!

Please update support for new versions FF (55+)