I don't use emacs but vi on all of my devices. This should probably work with emacs stuff if they save it in regular files/directories. I put everything in ~/notes. Quick sync before leaving the house, sync when I return. Can use your desktop as the central location if you don't have a home server. Works with termux on android. I think iphone has iSh or something for alpine.

Swap src and dest as necessary (could use other options but this is compatible with OpenBSD openrsync): rysnc -rlpt --delete notes/ user@lanip:notes