@somatalos @boo_ some apps work like that yes.

The big problem seems to be that there's no way for iOS apps to read files from arbitrary folders, say documents or downloads.

Each app must use its own directory for storage, which defeats the purpose of what I wanted to do - nextcloud sync to local files, and some other tool would play them.

It is such a simple thing yet impossible to do on iOS. Ironic that 10+ year old iPods can do this task much better wtf