Syncthing

Peer-to-peer file synchronization application. It can sync files between devices on a local network, or between remote devices over the Internet.
— Wikipeida

Resolve conflicts

I widely use it to sync my notes, books, photos, etc. between my devices.

To resolve conflicts I use syncthing-conflict-resolver.

Usage in my case very simple. I go into directory with conflicted files and run syncthing-resolve-conflicts -d . -f. It will show me conflicted files and ask me what to do with them.

Setup Syncthing on Kindle Touch

Original source - Magically format embedded languages in Neovim - YouTube.

1. You need jailbreak and KULA first.
2. Download this repository
3. Download syncthing-linux-arm and copy syncthing binary to syncthing/bin/
4. Connect Kindle Touch to Your PC
5. Copy syncthing/ to KINDLE-ROOT/extensions/syncthing/
6. Select “Open Firewall for Kindle” from KUAL
7. Select “Start Syncthing INSECURE Admin” from KUAL
8. Find out your Kindle IP address by type ;711 in search, then open http://IP-ADDRESS:8080 in your browser.
   
9. Configure all peers and folders
10. Ignore kindle auto generated index files: *.sdr
11. Select “Close INSECURE Admin port” from KUAL (Optional, for security reason)
12. Select “Stop Syncthing” and then “Start Syncthing” from KUAL
13. Note: connect kindle to computer or restart kindle will terminate syncthing process and firewall.