SpiderOak Semaphor [video]
spideroak.com
spideroak.com
Semaphoric patterns are used in the application as a more visually appealing means of peer key verification, device provisioning, etc. than say, QR codes.
It seems like it's Google Drive/Dropbox with end to end encryption, but part of the copy is about how people "used to work with files and folders", implying that they no longer do. If there are no files it can't be Dropbox, can it?
10 years ago SpiderOak made a zero-knowledge cloud storage product which is now called SpiderOakONE and is comparable to Dropbox. Semaphor is a new app, analogous to Slack or HipChat, with end-to-end encryption, and team/enterprise focused.
It's written in Golang with the client side (local) presentation layer in React. Source and a white paper are published. Cheers!