I don't have any apps to recommend but it sounds like you and others interested need to contact the map companies and favorite developers to express interest in RT apps.
As far as including GPS or not, it is a calculated cost. It certainly adds to the cost of the device but how much depends on may factors. It might include actual chip cost, design cost, software cost, battery life and supply cost. It is possible that all of the capacity for chips including GPS is already being taken up by all the other devices that include it (phones primarily). MS is using Marvell for its chips and they went with MIMO wifi, bluetooth, FM instead. They probably figured dual band wifi and bluetooth were going to be primary use case and just left it at that.