The android application does not support the automatic screen orientation. I tested it on smartphones, and obtained a portrait default screen mode. I tested it on 10-inch android tablet, and obtained a landscape default screen mode.
I need to purchase a 7-inch android tablet to use Collector for ArcGIS. So I'm wondering for screen size and/or screen resolution make the application switch between portrait and landscape default mode?
Can we expect soon the support of the automatic screen orientation as the Collector iOS app?