Marvel + Sketch Prototyping - Your Sketch workflow, reimagined
DelaFil - Share files in an easy way. One, two, three and its Sent! Instructions:
UX Flow Wireframe Prototyping System - Create beautiful user flows prototypes for your next project
EasyUpload.io - EasyUpload.io is a file sharing and file transfer service that allows you to upload and share files.
ProtoPie - ProtoPie is the easiest tool used to turn your UI/UX design ideas into highly interactive prototypes for mobile, desktop, web, all the way to IoT.
WeTransfer - WeTransfer is a free service to send big or small files from A to B.