Has anyone made a DMs-only fediverse client? Like something that looks more or less like iMessage or Signal but you address people via their fediverse handles and it handles DMs as first class (and only-class) content?

Has anyone made a DMs-only fediverse *server*? Like if I want to join fedi but only to direct message people and be in group chats I could join a server and it would have a nice client view like the one in the previous paragraph?