1) Create a hybrid app which runs on both Android and iOS.
2) Make this hybrid app connect to an SSH server and use 'scp' command to copy a test file from server to local phone storage.
You can provide your own test file and test against your own SSH server.
This is a research POC project.
I would suggest starting with
[url removed, login to view]
This seems to be the most complete plugin available for this task, but is a couple years out of date.
The task here is research if this plug in will satisfy requirements above and if not, give an estimate on additional time need to get it working.
Thanks for the invite! I recommend going with something like [login to view URL] and the npm module simple-ssh.