NDK (Highlighter etc), Snort, Coracle, Gossip, ZBD Social, njump are somethat I know.
Discussion
Stemstr
ZBD Social, you mean that client that won't let 99% of Nostr access it? 👀👀👀👀👀👀
Disco shit too.
😉 
Why do you say that?
It's a special kind of client for ZBD users only: https://fiatjaf.com/d36862b9.html
I know about the client, but it's locked behind an invite spam wall.
Why is that so bad?
It's a model that I have begun to despise over the years. I don't want to whore myself out or my followers out to gain access to something. Just give me access. If it's good, the product will speak for itself.
Well, you don't have to whore yourself, you can just wait. Beta testing is good to help iron out some bugs, but I personally would never do anything like that. I would just wait or not pay attention and move on.
But I think you're probably not the target demographic for ZBD Social. Which should be a good sign, sign that Nostr can reach other kinds of people that aren't the technical/very-interested/early-adopter/freedom-focused type.
They too cool for us