Hello,
I'm the creator and designer. I'll be happy to answer questions you might have about Vuash.
The project started as a little tool for me and my colleagues to exchange wifi passwords, environment secret keys etc. during our daily job routine. There were a couple other similar services available at the time (that we knew of), but we didn't like their UI, UX and overall tech, so we decided to make our own.
The first version needed SSL to encrypt requests because the encryption was all done in the server, but since version 2.0 we don't need it anymore, as the only thing that touches the server is the already client-encrypted message. You can read more on how it works here: https://github.com/current/vuash...
Vuash is free to use, supported by donations, and open source.
Vuash