The migration app of choice appears to be .. xiaohongshu, or "little red book". I'm guessing this won't last since it wasn't intended to have lots of Westerners using it and neither government is going to be happy with that scale of unfiltered contact between ordinary Chinese citizens and US citizens. In the meantime, it's the place for Luigi Mangione memes.
In English, it seems to be called rednote. But I doubt that it will be a real successor. At the moment it's a funny meme, and for some people satisfied cultural curiosity. But we already see the problems appearing, from the poorly localized interface, to people getting banned for reasons outside their understanding. My guess is, at the end we will see maybe some million users from the USA and some more millions from…
Rednote could be a fad that fades, but technical problems won't be decisive.