The Linux way:

• write a script: you can use the find command to find for example rars in a folder. find ~/thatfolder -iname ‘*.rar’ -exec uncompresscommand. Read ‘man find’ for specifics. Script’s first line is #!/bin/bash. Say ‘chmod u+x script’ to make it executable.

• set up a systemd timer unit that calls a service unit that runs your script at intervals.

• you can use something like for file in ~/thatfolder/* ; do sed trick that extracts the file extension and puts it in a variable ; case $variable in ; bunch of cases for different extensions. Variable $file will hold the source file name. Read up on bash scripting to figure it out.

Welcome to penguinland :D

I just tried. Old app exports a directory, new one wants a zip. Zipped the dir and offered to new one. New one complained that some expected file was missing. Gave up and set it up again with it’s new keys (phone only syncs one dir off my home server, not a big deal) and now it’s going great.