AFAIK there is no polished standalone frontend for jj yet. https://github.com/gulbanana/gg comes closest but I ran into some quirks when using it on git compatible/colocated repos.
Someone has made a VSCode plugin but it's closed source and I believe it will be paid at some point? https://www.visualjj.com/
Kudos for the article. I have been seeing jj here and there, but this is the first that made me want to try it.