Within the App Designer, you can set the record title property which will display on the web or mobile as the primary identifier for a record. On the mobile applications, this is the attribute that will display in the preview when tapping on a pin, or as the main identifier in the table layout.
Up to 5 fields within the app can be appended together to set the record title. It is a good idea that you make sure at least one of the fields is a required field. If no fields being used for the record tile contain values Fulcrum will use the first text field that contains a value as the record title until the fields have values.