Tools for moving files between computers

I have not vetted or reviewed any of these tools. I also do not condone using any of these tools for illegal activity!

Tools that use Tor

• OnionShare -- Offers both a GUI and command-line tool (would recommend using pipx to install the CLI: pipx install onionshare-cli).

CLI tools

• Magic Wormhole
• croc -- written in Go, looks good
• qrcp -- for transferring to and from a mobile device.

Cloud-based file transferring services

• Bitwarden Send
• Standard Notes FileSend

Also helpful

• Dangerzone (GitHub) takes potentially dangerous PDFs, office documents, or images and converts them to safe PDFs
• age is a new PGP alternative for encrypting/decrypting files
• Cwtch now supports file-sharing, but the tool is, overall, still in beta as of this writing.

A GPG GUI, if you must

sudo apt install gpa installs a GUI called "GNU Privacy Assistant". You can read more about it here.