How to copy files/directories using Web UI only?

I have a working OC ver.8 system with an Web UI extension that lets me copy/move files/folders around very easily. The tool lets specify the destination folder, and it can be every folder in the filesystem; the tool is not constrained by the drag and drop routine like the default Owncloud setup.

Specifically this extension lets me copy files; which seems to be a no no with OC 10.
There seems to be nothing like that for OC ver.10 ... or am I missing something?

The app market looks pretty "dry" at the moment. What happened to the old extensions?

Someone should correct me if I am wrong, but extensions live and die with the people's interest to work/maintain them. So if there is no interest anymore - they get unsupported. You can look for the desired one on github and try to implement it in your installation of course.

There is no extension that I know of that does what you want ATM

I wish I could write it my own, but I don't have the needed skill/knowledge.

There's something on Github but seems too old and I can't get to test it on my OC10 system any way :