If you have an old phone or a tablet at home, you can even skip the server step since you already have an always online, low energy consumption device running anyway.

This uses some pretty terrible criteria. Being critical is imporant, and slopware should be looked upon very spektically. But please do this properly and dont slop together questionable lists.

Total Commander for Android has an SFTP plugin. They run their own fdroid repo.

https://www.totalcommander.ch/android/plugins.htm