Doesn't look like it's going to be open-source, so the "safe" part will be hard to independently verify.
Meanwhile it's also XMPP-based, and so it looks like it will be yet another centralized service, with servers run by Hemlis themselves. (Don't get me wrong, I'm an avid XMPP user, but I believe in freedom to choose my own software and service, including my own.)
If it's not just another closed proprietary service, it would be great to see more info about that.
This looks promising. You say built "on top of proven technologies, such as XMPP with PGP." Okay, these are all or some of the technologies. Why use PGP when OTR is proven to work with XMPP, and is even better than PGP in some respects (I am not a crypto expert, but I do know that the OTR protocol provides PFS and PGP does not)? Unless you detail how the underlying crypto works, I will be skeptical.
Because OTR needs both users to be online when sending each other messages, which is not a fair assumption for mobile users. You need to support offline-messaging for a mobile messaging app to be viable.
I like the idea of trying to combine good looks and usability with secure communications. But with no source code, and no mention of OTR, nor of free-choice-of-server, I'm not very hopeful.
Perhaps they should just create pretty skins over Gibberbot and Chatsecure instead :-/
Meanwhile it's also XMPP-based, and so it looks like it will be yet another centralized service, with servers run by Hemlis themselves. (Don't get me wrong, I'm an avid XMPP user, but I believe in freedom to choose my own software and service, including my own.)
If it's not just another closed proprietary service, it would be great to see more info about that.