Quite new to WaniKani - I hung off for ages because it’s not comfortable to use on mobile and my old laptop was too slow to even bother turning on for kanji practice!
A couple of first impressions:
Quite a few times already I’ve been ‘held back’ on a kanji because I got it wrong and pressed Enter before remembering to manually open the notes and check the correct answer. Then when the same question was asked again, I still had to pass. Why doesn’t the helpful info automatically display when you get a question wrong? 
Second: partly why I’ve been skipping prematurely - I’ve already been conditioned to bash the Enter button twice in quick succession after every question to get onto the next one a little faster. Why isn’t once enough if the answer was right?! It used to be like this on Memrise and it drove me mad there as well. 
Other than that, WaniKani is by far the best training resource for Japanese reading skills that I’ve come across. Go WaniKani!
