Not sure about AI specific but: Todo apps, habit trackers, lots of social media, job boards, recommendation apps, fun things to do with friends, travel planners, trackers (movies/books). I think it’s more common for B2C because these are things that a lot of people come across.

Some of these ideas could maybe be done better now that we have genAI but the question might would it work as a standalone app or is it just a feature?