Kafi on Nostr: I think all is pretty straight forward, so easy to use. Modern and minimalistic ...

I think all is pretty straight forward, so easy to use. Modern and minimalistic interfaces on all their applications (PC-Clients, Mobile Apps, Webapp). Not super customizable, but it does all it needs to and looks good and very modern.
And I have also seen them improving a lot, since I use them. Check their Blog and Roadmap. They really listen to their customers and if they can, they will bring in new stuff, as long as it also fits their philosphy about privacy and stuff, which I really appreciate.
Some things are not there yet, but that again is also because they take privacy very serious.