The historical mapping project on Wikimedia Commons - Wikimaps - https://commons.wikimedia.org/wiki/Commons:Wikimaps uses an application on the Wikimedia Labs system https://warper.wmflabs.org to help georeference and rectify the images of historical maps. It uses OAuth for authentication and if the map's wiki file page has the special Map template, will edit the page to update the values of the "warped" and the "latitude" and "longitude" parameters if changed in that map template when the map has been georeferenced. It leaves an edit summary explaining the edit.
(Note for approvers: This consumer application v.2.2 is configured for the HTTPS endpoint on wikimedia labs. It would be good to also keep v2.1 which was set for HTTP)