CONV. - Convert YouTube video to MP3, GIF or MP4
Bashupload - Upload files from command line to share between servers
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
FilePizza - Open source application used to transfer file via WebRTC and WebTorrent.
Yout - YouTube to Mp3 Converter
BlackHole File Transfer - Blockchain-based file transfer. Designed for everyday use.