Dropbox - Online Sync and File Sharing
XShare - XShare – File Fast Transfer developed and published by Shalltry Groups.
Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...
Zapya - Zaypa is a cross-platform transferring and sharing!
Nextcloud - With Nextcloud enterprises host their own secure cloud solution for storage, collaboration & communication from any device, anywhere.
SuperBeam - SuperBeam is a file sharing app that makes moving files across devices much easier by using technologies like NFC and QR codes instead of plug ins. It is one of the fastest was to move files from one device to another.