I really recommend KaniWani as a companion app, especially if you’re hoping to speak and/or write. Whilst WaniKani is great for recognising kanji and words, it’s not so good for recall.
KaniWani tests you the other way, so you have to provide the Japanese reading for an English word. It also syncs to your WK account, so it progresses alongside.
I hear there’s an app called KameSame that does pretty much the same thing, but I’m in too deep with KW now to test it out
Personally, I hate Tae Kim’s Grammar Guide. I don’t like the layout. It just doesn’t make sense to me the way it’s organized. I suggest Imabi for grammar.
I also own Genki and have been going through them, and I’d recommend them if you’re someone who learns well with books like I do.
I’d also suggst using a podcast like Nihongo con Teppei for listening practice. I also like Japanesepod101 so far.
I also watch kids shows like Doraemon. I don’t really understand them yet, but I have been able to pick out a few words and phrases here and there
I’ve always stayed away from YouTube channels because I’m more of a book learner, but I just started Cure Dolly’s Organic Japanese series and it’s great! It’s so addictive and easy to understand. I’d give it a try if you’re not a fan of textbooks.