When I was using Windows to manage my files, I always open a lot of windows to move my files. Even the window is already open, I will open a new window. Because it is difficult for me to find the opened windows. And my taskbar will full of tasks.
Moving to Ubuntu, Nautilus is the default file manager of Ubuntu. I face the same problem as using Windows. So, the software similar to FreeCommander on GNOME based OS is GNOME Commander. It is very useful.
However, I just found that delete files using GNOME Commander does not move the file to Trash. This is a drawback.