Keybase Chat - End-to-end encrypted chat built into Keybase
RoxyApps Share me Files - Send your files to other users without any registration. The application provides extended options of uploading and storing files
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Starfiles - File hosting done simple
Seald - Keep your conversations secure, everywhere.
Droplr - Droplr is a tiny application that aims at helping people share things easier.