IIRC, those are "partially weakly anonymous". There are no pseudonyms in Secretly for the "main" posts - they are anonymous, even though the anonymity isn't even remotely strong. Machine-generated pseudonyms (identicons) are used only for discussion comments there -- don't know about Hush, though.

Either way, there's nothing revolutionary about this sort of apps, but marketing statements. Anonymous BBSes are there for decades, and this app has exactly the same concept except for being a mobile app instead of a website or desktop one. The only relatively novel part here is location-awareness.