Anyhow, my tool is on GitHub too[2], although it's incomplete.  The category mode is working fine, but it was originally started (long ago) as a downloader for preparing images for offline Wikipedia editions, based on an article list, and supporting multiple parallel downloaders, and that part is incomplete.

Awesome! The more the merrier :)
I'll get around to finishing that Some Day Soon.  

Ah, I certainly know the feeling ;)

I actually got around to finish that tonight :

sudo pip install commonsdownloader
download_from_wikimedia_commons --category 'Images_from_Wiki_Loves_Africa_2014_in_Ghana'

Hope that helps,