I have a distinct memory of there being a BBS client for either the Apple II or maybe the IIGS called something like "Graphical BBS". I'm pretty sure that it used the Apple II hires mode. But I can't find any evidence that it existed for the Apple II series and I've been searching off and on for years.

Wait... I just searched again. I'm not crazy. It was called HBBS and it got added to archive.org last year:

https://archive.org/details/apple2_hbbs

Oh, no, its author (Matthew Dornquast) passed away earlier this year:

https://www.startribune.com/obituaries/detail/0000416768/

Jason Scott (textfiles.com) posted about his passing at the time:

https://nitter.net/textfiles/status/1490157005805395971

Well, now I'm bummed. I found what I was looking for all these years and sadly learned its author died much too young.

:-(