Here’s my Anki deck. This already contains all the missing jōyō kanji as well as a lot of jinmeiyō kanji and a few miscellaneous other kanji: Remaining Jōyō Kanji Anki Deck. This is my own personal study deck so it’s not perfect but I hope you find it useful.
I can’t speak for WaniKani but I recall reading once that many of the remaining kanji are only in the jōyō kanji set because they appear in Japan’s constitution.