

krusader is a dual-paned file manager for KDE. It runs on Linux (of course), MS Windows, and Mac OSX.
Folder sync is what makes krusader outstanding, even if you don’t care about dual-pane file management. Open the two folders you want to sync in the panes and go to Tools > Synchronize Folders. You can synchronize both ways, exclude files, delete lone files, etc. Very powerful.
Being a KDE app, krusader does not skimp on features, so there are lots of other things that krusader can do.
link: https://krusader.org/
krename is another excellent, but not as well known as it should be, KDE app.
krename can rename files and directories, and directories recursively, to almost anything. You can rename:
or with a mix of everything.
krename has a simple mode and an advanced mode for renaming, so you don’t have to jump into the deep end with the features.
You do have to be careful with some of the file info functions - it will happily try to rename a movie or a pdf with (non-existent) image EXIF info, for example. That would result in a file with a name you did not intend.