both applications let us create characters for this
https://play.google.com/store/apps/details?id=com.Beauchamp.Messenger.external&hl=en&gl=US - PC with limited support but works on mobile devices
https://kajiwoto.com/ - this one supports PC and mobile devices
after creating your AI companion you then have the option of sharing it with others
I setup a bot on Chai called Hestia (kisses)
But haven't configured her to be like the anime hestia