I'm seeing a lot about them too. They seem to be going viral because of their sexy avatar that talks about how they are using AI to make people better versions of themselves through their mobile app. I didn't download because I'm iOS and it's Android-only now, but my friend did and he says that it actually is worth the hype because you can have natural interactions with the avatar (not the Siri/Alexa type) and it has its own personality. From my understanding, the avatar is supposed to help motivate, and blockchain element kicks in as part of a rewards system and helps cater to privacy concerns as well. Yea, I'd say it's legit, with all the work going around it and conversations from people all across the globe.

Yoo-Mi PHA is making a huge splash these past couple of weeks. Can't say I've seen or heard anything negative about it either. I'm looking into it myself, only seeing good feedback.