As of my last update in January 2022, there isn't a specific extension called "Cmd J – ChatGPT for Chrome." However, it's possible that such an extension may have been developed after my last update.
That's really a time saver — I've been using ChatGPT for a while and switching other extensions didn't work so well. Tried cmdj today and that's much better.
Small feedback: I couldn't figure out how to make ChatGPT track context so it would be within the same question I asked before — seems like the extension creating a new context for each question? Is it supported right now? Maybe some hint of what dialog is happening with ChatGPT right now?