It's also available on GitHub if you're not interested in the Mac App Store: https://github.com/televator-apps/vimari
It works pretty well, but I've strayed away from using Vim & Vim bindings for everything after getting into using Emacs on my Linux box at work.
There is also https://github.com/televator-apps/vimari the Safari port thought it is not full featured as vimium.
So is Karabiner (https://wiki.nikitavoloboev.xyz/macos/macos-apps/karabiner) to map opening apps to two keys.
Some nice people have kept one alive for Safari as well https://github.com/televator-apps/vimari but there's only so much they can do. It's almost useless.
I tried Vimium-FF (https://addons.mozilla.org/en-GB/firefox/addon/vimium-ff) and many other Vim like add-ons in last 2-3 months (after I decided to give Firefox another try after Pocket; and the possibility of ditching MacOS in my personal usage), but no, these plugins are nearly nowhere as useable as they used to be. Page reloads, redirects, weird behaviours at anything I try to do.
Maybe I can spend hours (over days) and have a perfect config file and maybe, just maybe, it will work as intended but then again it might break with next version or next browser update/upgrade.
My most used features were "/" followed by "n" and "shift+n", "t" -> open and "w" -> close tab, "f", "o" -> getting focus in address bar. I think I will rather give up.
Somehow I don't like to tinker anymore in the personal computer usage scenarios and maybe it's people like me who have caused/convinced companies like Apple to close things down and try to make apps and machines simpler (at which they have failed specularly).