Launchpad currently recommends translating gnome-control-center in Ubuntu Cosmic.

Template "gnome-control-center-2.0" in Ubuntu Cosmic package "gnome-control-center"

Language Status Untranslated Need review Changed Last Edited By
Cherokee 100.00  100.0% untranslated 1597 1597 0 0
Dakota 100.00  100.0% untranslated 1597 1597 0 0
Hawaiian 100.00  100.0% untranslated 1597 1597 0 0
Inuktitut 100.00  100.0% untranslated 1597 1597 0 0
Lakota 100.00  100.0% untranslated 1597 1597 0 0
Ojibwe 100.00  100.0% untranslated 1597 1597 0 0
Spanish 000.00  100.0% translated 0 0 235 235 2018-08-03 14:20:03 UTC 2018-08-03 Daniel Mustieles
Tlingit 100.00  100.0% untranslated 1597 1597 0 0
Yiddish 100.00  100.0% untranslated 1597 1597 0 0
[ Change your preferred languages... View template & all languages... ]
Key to this table: “Unchanged” means Translated
and “untranslated” means just that, Untranslated

Other versions of gnome-control-center in Ubuntu