Please note that I haven't tested any of this yet.
Packages list (some may be missing):
* gnustep-{make,base,gui,back} and related dev packages
* gdl2
* easydiff
* edenmath
* pantomime
* gnumail
* gorm
* projectcenter
* gworkspace
* gnustep-examples
* laternamagica
* lusernet
* notebook
* poe
* terminal
* textedit
* systempreferences
* vindaloo (with iconkit and popplerkit from Etoile)
* waiho
* renaissance
* zipper
* helpviewer
* cynthiune
* dbuskit
* addressmanager
* agenda
* fisicalab
* performance
* rsskit
* grr
* price
Everything is under the following url :
http://coyote.octets.fr/pub/gnustep/packages/
For example, for trusty amd64 you can add to sources.list :
deb http://coyote.octets.fr/pub/gnustep/packages/trusty/amd64/ ./
Please let me know if you find this useful, if a package is broken, if
you would like to add another package to the list etc.