Pushbullet - Pushbullet - Your devices working better together
Bashupload - Upload files from command line to share between servers
blymp.io - Transfer files between any device with 4-digit codes
FilePizza - Open source application used to transfer file via WebRTC and WebTorrent.
Plover - Browser Airdrop - transfer files to anyone, any device
BlackHole File Transfer - Blockchain-based file transfer. Designed for everyday use.