In the advent of forced updates being shoved down our throats due to some addons becoming unavailable and websites supporting legacy browsers more and more, this is a very similar alternative to the old, now outdated Rikaichan.
It gets the job done well enough and uses the same key bindings for the ones it has in common.

However, it lacks in quality of life compared to its predecessor.
There doesn't appear to be a way to change the font size with the text appearing a bit more bloated (and spaced) than I'd like, it removed the ability to put the frames in set corners on the screen using the "a" hotkey (I never used this personally, but was aware of it), and it doesn't allow you to change the order you "shift" through (always being word definition, kanji breakdown, names dictionary) like you could on Rikaichan.

The worst part would be that when switching to the names dictionary for Japanese, when there's so many options to fit on screen it will just make one super long column stretching off the screen instead of splitting it into two columns, effectively making half the options unreadable without zooming the page out by a good chunk.

In the end the important part is that if it works, though, which it does.