Syncthing - https://syncthing.net/ https://syncthing.net/ Before I explain my setup, realize a simple one-way, two-device setup can be done quickly and easily.

Syncthing - https://syncthing.net/ https://syncthing.net/ Before I explain my setup, realize a simple one-way, two-device setup can be done quickly and easily. https://docs.syncthing.net/intro/getting-started.html https://docs.syncthing.net/intro/getting-started.html I have it set up on my phone (android), desktop (Devuan), laptop (MX Linux), and a server (DietPi). I have the DCIM picture folder synced one-way from the phone to the server, and one-way from the server to the desktop and laptop. As soon as a new picture is taken and a network is in range, the photo is synced. I also have separate sync folders set up for other purposes: "music" - all-way, all devices. "keyring" for password manager - all-way except one-way to phone. "sync" - All-way, all devices except phone. "syncmobile" - all-way, all devices Right now sync only happens over WiFi connections (local and remote) for "reasons". It's been that way for years and it's been enough. I'm still contemplating cellular data.