Wanikani does a wonderful job of helping us build up our knowledge of Kanji incrementally. But as the number of Kanji I have mastered grows, I wonder about a problem. Maybe it has been solved by an add-on, but if not, here are my thoughts:
Would it be possible to have a hint feature? My idea would be that during a review if you pressed the hint button, you would get a sentence that used the Kanji about which you are being asked. Excessive use of the hint button could be discouraged by giving only half a credit for having answered correctly after using it. But often I find I actually know a Kanji but seeing it in isolation isn’t enough to prompt me to remember it properly.
I realize such a feature would take time to develop, especially if you wanted to add bells and whistles, such as second and third sentences or phrases that would appear each time you pressed the hint button, each perhaps a little more helpful than the previous. But I think it would help bridge the gap between learning each Kanji somewhat in isolation. And in real life, we can often tell what something means from the context - and Japanese is the ultimate contextual language.