How can I restore one app’s data from an encrypted iTunes backup (iOS 11.3.1) to the same app on iOS 11.4? I deleted the Readdle Documents app by mistake and I had some files in it I would like back. I would prefer free or open source tools if possible. I am using Windows 10.
(I don’t believe this is possible in iTunes. I tried iMacTools’ iBackup Viewer, and it only extracted what seemed to be placeholders for my files. (See answer below.))