An updated version of the French translation files is available to download here.
I would like to thank Pierre le Lidgeu, a collaborator of the translation website www.colok-traductions.com, for his precious help.
To install the language files, download the corresponding zip file from this list.
Next, extract the entire content of the archive to iCopy executable folder (typically, C:\Program Files (x86)\iCopy).
Start (or restart) iCopy and go to the settings window. The language should now be listed. Choose it and restart iCopy.
If you would like to contribute to the translation of iCopy, please check this page.