I started using the Chrome extension Wanikanify, and I love it, because you study your vocab without even thinking about it.
I also made mistakes between reviews. I ended up resetting back to nearly the beginning of the course because I was feeling overwhelmed and wanted to take the time to learn how to write as well. I was unhappy because the course teaches you recognition when you see the kanji paired with the hiragana, but to remember them without prompting is a whole different story. The self-quiz userscript is really helpful also because you learn the words without prompting.