My school iPad updated to the newest iOS 13.1.3. I have an app that I use to record tests and the backup file can only be opened using that specific app. Before the update, when I clicked on the file, I was given the choice of what app to use to open the file and I would choose that app. Now, I am given the usual apps to open the file with, but not the app that I need. The app has updated as well and is otherwise working fine and I can't find any way to add this app to the list of apps to choose from. Any idea why the app would no longer be available as a choice? Any idea how to add the app as a choice? I emailed the app developer, but so far I have heard nothing.