This is a third-party app and is not created by the WaniKani team. By using this, you understand that it can stop working at any time or be discontinued indefinitely.
I only use it for the Double Check script but really - WHY can’t we just have an undo button and then I wouldn’t need it. Yes, I understand that people could possibly cheat, but what would be the point in that? And also - what does it matter to the devs if someone cheats anyway?
It’s just really annoying when you get something marked as wrong because of a typo, or when you write a word that means the same thing as the answer and it’s marked wrong (yes, I am aware of the function to add synonyms).
I really don’t think there is a good reason why there isn’t an undo button.
The issue is that they try to tell the difference between a typo and an error. If there were an undo (or “mark as correct”) button, they could stop wasting their time adding synonyms and fuzzy logic and let the users figure it out.