Hey Rob,
No problem- happy to help.
We're encouraging people to use Explorer in place of the ArcGIS app because of its modern and intuitive user interface. Explorer is the premier app for data discovery, exploration and map use.
In the longer term, we do not plan on having any further updates to the ArcGIS app. Explorers future releases will have new capabilities that include support for offline maps, editing features, support for time aware layers, 3D and analysis.
I hope that clarifies things a little.
Regards,
Nick