I made Homerow, it's the same idea as Vimium, but for the entire macOS user interface.
On an unrelated note, I made the same thing (barebones), but for Linux and theoretically also Windows: https://github.com/phil294/vimium-everywhere
I would also like to note that the Shortcat dev plans on adding licensing. Homerow has licensing, but there's no blocks on features. So they are both "free" in the same way.