We desperately need a way to export a description of an app. Evidently Knack apps are defined by data - either a set of tables or some sort of XML or JSON structure.
I am not asking for a way to restore an app from description. But having any sort of vaguely readable (set of tables, XML, JSON...) and complete description would allow us to make real backups. We can 'clone' an app, and later compare the description of the current app with the description of the cloned one. We can store our descriptions in Git or other source-code-control systems to track changes and make it somewhat more possible for multiple developers to maintain a single app.
Given that this is a developer feature, I think it would be entirely reasonable if it was only possible via the API. Honestly whatever is the simplest solution for Knack to implement! Knack apps are defined in data somewhere - just give us access to that data for our apps.