Mine is Blushcast: https://blushcast.com/
Full disclosure: I’m involved with the project. It is an 18+ library that brings original adult fiction, audio stories, guided audio and interactive stories together in one place.
The interactive side is the part I’m most interested in at the moment. The aim is for choices to change the conversation, pacing or ending instead of only changing one sentence before returning the reader to the same route.
All characters are adults and the content is fictional.
I would be curious which format people here actually use most: written stories, audio, or branching interactive fiction?