In bed, too early to sleep so decide to watch a film. Too lazy to go fetch my laptop.
So I use #ConnectBot to open an #SSH session on the laptop and run #kdeconnect's kdeconnect-cli -d xxxxx --share file:///path/to/that/film.mp4
And watch the film on #VLC on me phone.
If I hadn't been on the same #LAN I would have copied the file into my #Nextcloud directory and synchronised from there.
All the apps mentioned available on @fdroidorg.