Two feature requests I would love:
1. The ability to "scan" in a document as part of an app submission. For example, adding a receipt to a work closeout form by taking a photo of the receipt , the app detects the edges of the document you are scanning and converts the photo to PDF. I do this now using photo submission but the results and clarity of the photos are poor. iOS has this functionality built into its "Notes" app now.
2. The ability to add in an attachment to any PDF submission. For example, you receive a purchase order from a customer, you start a work order using a GoCanvas app to fulfill it and you attach that purchase order to the resulting PDF.