In case anyone else who has an Atom Node that wants to try out the BeaconUI Android app (a working version) I finally found one here:
https://github.com/yexiaobo-seeedstudio/BeaconUI
the .apk is in the /bin directory
I tested it and works fine on a Samsung Galaxy S6 running Android 7.0
Now, the next question is… where can we find a direct replacement battery for the Atom Node? It seems to use a 10440 Li-ion, but I’ve not been able to find one with the protection circuit and leads/connector pre-soldered. The closest I’ve found so far is one that has tabs that would allow me to remove the connector from the old battery and solder them to the new one, minus the protection circuit board.