Sometimes a user sets up a Field Maps project, goes into the field, and while they are collecting data, discovers they could use another field. Maybe they forget to add a particular field during their initial setup, or maybe as they were gathering data they realized there as an additional parameter they want to record.
If all they have with them is the smartphone on which they are running Field Maps, then it is not easy to get to ArcGIS Online and add a new field to their feature layer. For instance, on an iOS device, even if they use "Request desktop site" in a web browser, there does not seem to be a way to get the "+Add" button for fields to appear in the Item Details view of a feature layer (Data --> Field.) Nor can one add fields in the ArcGIS Companion app.
It would be great if one could add new fields to a feature layer directly from the Field Maps app.
There would presumably be some limitations, such as only being able to add a new field when working online, not being able to add a new field if offline replicas of the feature layer exist, perhaps being stuck with a default visualization style, etc.
