Working now.  As it turned out there were two problems:
1) I was using a Chromebook (Acer R11) to run the app.  It connects to the loco and looks like it is working but apparently is not actually communicating.  When I switched to an LG phone and ran the app it immediately asked to update the firmware and listed a real firmware number.  So while many apps run fine on Chromebooks apparently this isn't one.
2) The track power supply I was using was one that was handy (not packed away).  It was an RC controlled power supply from Life-Like.  As I checked voltage at the track I noticed that as soon as I moved the throttle in the Bachmann app, the voltage dropped to 0.  SO: apparently the Life-Like RC controller gets interference from (some, not all) bluetooth transmissions.  I dug out another power supply and - finally - the app on the phone could run the loco.  I like it.

Maybe this has happened to someone else?  I buught an EZ-app loco from Amazon.  Set up a basic oval of track to try it.  It connects to the android app and the loco cab light comes on then goes off.  After that, nothing.  Can't turn light on with the app and loco doesn't move (or attempt to move) with throttle.

Likely unrelated: In the app, the firmware version shows as 0.0.  Seems odd.

Help?