The script is updated now. 
Thanks for the update Sean.
I have a version of this which also works for the Review Details also.
I’m no programmer but simply changed Lesson to Review throughout your script and was surprised to find that it worked on all WK pages.

Unfortunately it does not work with the new dashboad page any longer even with your new change.
Is this something you might be interested in getting it to work?
You probably just need to find the proper class in the HTML for the new review button. If you inspect the element (from the right click menu) you can probably find it.
Thanks for the “answer” Sean but maybe I should stress the bit where I say “I’m no programmer”.
I know nothing about HTML 
I saw that, but I thought maybe you’d be interested in learning a bit. 
Yes, I appreciate that too, unfortunately I don’t even speak the same language because I couldn’t even tell you what a class is here, sorry.
I am also quite surprised. I want this too!
Duplicate the script and find and replace will do the trick @Kumirei
(at least for the other pages now).
… but who am I to give you any kind of technical advice?
I’m legitimately curious, what is the appeal of this feature for reviews? Don’t you just do all your reviews anyway?
If time is limited I will only do R’s and K’s
I work up a backlog every now and then and like knowing what’s in it when I do
Gotcha. Well, if at the top of the script you change lessons-and-reviews__lessons-button to lessons-and-reviews__reviews-button it’ll probably work.
For future reference, this is what I saw when I right clicked the new review button and did inspect. Each class is separated by a space and I picked the one that seemed unique.
Ahh thank you Sean.
I see where I had gone wrong now;
by blanket replacing lesson to review I had changed
lessons-and-reviews__lessons-button to reviews-and-reviews__reviews-button
which wasn’t going to work was it.
Appreciate your help.
Thank you. This seems to work perfectly. As for the appeal of this feature for reviews, it is nice to get a glimpse of the breakdown before starting – even if the intention is to go through the whole batch. 
I’m glad the script is working well for you. 
For a review version, perhaps someone can make a script (if one doesn’t already exist) that shows this information. I’m no longer making new scripts, but it probably wouldn’t be too hard to make. If you post a request (perhaps here or in a new thread), maybe someone will help you out.
EDIT: Thinking about it more, I feel like @Kumirei made something like this.
Oh I had actually meant that the tweak you suggested to AlliCrabi in a previous post was working to get the same sort of breakdown for reviews as it already does for lessons.
change
lessons-and-reviews__lessons-buttontolessons-and-reviews__reviews-button
Although I now see the script @Kumirei made for this, which also looks great. The extra details aren’t really necessary for me at the moment, since I’m only level 4 lol…but hopefully I’ll get to the point where the full chart will be more meaningful. 
Oh, I didn’t even realize you were replying to the previous post. 
Can you include preview.wanikani.com in the included sites? I mean, I could do that myself, but it’s weird because the other scripts did that automatically…
I personally don’t think it makes sense to be included by default, as the script could completely break the user experience unexpectedly. I’d recommend turning it on there manually if you are testing it on the preview site.
