...from NSOU website,
Norfolk Southern has released an update to its mobile app featuring the ability to track and report sightings of the company’s 30th anniversary heritage locomotive fleet.
The latest version of the NS app, originally released last August, is now available for iPhone, with a version for Droid phones to be available later. “Heritage” gives users the ability to see where the NS heritage locomotives have been spotted and to report and post photographs of new sightings. Release of the app upgrade coincides with the display of all 20 heritage locomotives July 3-4 at the North Carolina Transportation Museum at Spencer, N.C., after which the locomotives will return to freight service.
My comments * and **...
*It does not state that there will be a listing of where the Heritage locomotives will be but where they are and recently were - based on postings. With some idea as to NSOU train schedules, one may be able to predict if a Heritage locomotive will be nearby your location so you can observe safely.
** Maybe GPS links can be added in future.
Hope this explains a bit more.
Walter M. Matuch