I know there is a thread about one made by Sleepy Flower Girl (
thread link,
github link), but afaik it broke or something.
I also have a not so well known Discord client which was once on github for a short time, but it was pulled because of a ToS change.
The reason I'm not releasing mine is because to my interpretation it seems like it's the client dev's responsibility for what the users do using it, and unofficial clients are not even supported by them in any way, ESPECIALLY not *user* accounts.
That's probably the reason why there is a lack of Discord clients for any platform