I bought the last version and ran it for a while. The one huge red flag is that they have access to all your contacts and messages via their servers. You can't upload your contacts directly to the phone from a USB cable or import them from a loccal file. You have to go to their website and upload your contacts and then they push them to your phone. The way MMS works is that the messages gets relayed to their servers, which then email it to you. It's an absolute security and privacy disater. Which is really sad, because almost everything else about the phone is pretty good and it's filling a need in the market.

[edit to add] as others mentioned, no TOTP auth app was the other requirement missing