[cassianoleal]

As much as it is open source, there's no way to know for sure that the software running on their servers is the same that's published on Github.

[restingrobot]

The software on the server doesn't matter, as long as the encryption is solid on the device. That's the whole point, the devices handles all encryption/decryption so the server can't understand any of the data coming and going. The reason they don't store the data is because it would be pointless. The Github repos contain the device source code which, for most platforms, can be verified.