Since I don't use any other form of SRS anymore, there are occasions when I'd like to add a word with no kanji to my lists. However what happens then is Skritter still attempts to quiz me on the kanji reading, but the field is just blank. I've been dealing with this by just marking it "easy" whenever they come up but it would be nice if the app would recognize that the word has no kanji and test only for the definition.

Hi there! It sounds like the easiest method to accomplish this would be to click the "All results" on the right hand side when searching/adding a word to your list (for instance if you were to press Shift+A from anywhere on the website), and then click "Not here? Add the word to our database." You could then make sure both fields are kana only so you won't be quizzed on the kanji writing/reading.