New answers tagged google
I've used GTFS editor https://github.com/conveyal/gtfs-editor , and it works pretty well. There is a moderate hump (usage of the command line) to get over for getting it up and running, but once that is done it's straightforward. If that is too much, TransitEditor is hosted and supported.
Transiteditor ,Transitdatafeeder and several other free and COTS tools are mentiond here https://code.google.com/p/googletransitdatafeed/wiki/OtherGTFSTools
Top 50 recent answers are included