I quite like the UI from the App Store screenshots, will have to give it a try.
Personally I’m not concerned about the licensing - anything that I would value (creative work, code, etc) would be posted on my personal website anyway.
I would however be more concerned about the long-term stability of the platform; there have been plenty of attempts before (App.net, Ello, etc) and none really took off. Outside of specific circles/industries (which already have established players - LinkedIn, Dribbble, etc), the appeal of a social network is that it becomes mainstream and everyone is on it, and personally I don’t see it happening with this one given it hasn’t happened with any of the previous attempts.