I've written several posts about what we use for learning Japanese, but I think that it's time to collect them and keep them all in one place: Japanese resource gathering for myself and my kids is a significant project. I have a two-pronged approach: we do some formal study, particularly Hero(10) and I, and then we do a lot of passive exposure and try to find ways to have fun in the new language. Here are some things that I like to use:
SRS or Spaced Repetition System:
If you're not familiar already, here's a quick explanation of what an SRS is.
I have been using Sticky Study for years, and it's working great. It's an iPhone app, which means that I've got it in my pocket when I have a few minutes, which is key to my success: 3 minutes here, 5 minutes there, it adds up to meaningful learning with time.
For Hero, I got the free version of Anki, which he uses on our desktop system. He does better with his stuff all at once, and all in a specific place, so the desktop system works great for him.
For Hero, we started with the basics: the alphabets, single words, a few grammatical definitions that he wasn't familiar with. Once he gains some fluency with those, he'll start to see phrases, and then sentences, and we'll introduce the kanji, starting with their meanings in English, which is surprisingly useful, even though you can't pronounce the words yet. My deck is primarily made up of sentences right now, though I do have some individual kanji that I'm working on learning some readings for.
For checking to see if sentences we want to say are correct, HiNative is invaluable. It's made by the same folks that bring us Lang-8, which is also fantastic.
For Native By Natives And Passive Exposure:
I try to expose us all, myself, and all three kids, to materials that are made for natives by natives. It's got natural pacing, expression, pronunciation... all the good stuff. And I try to make it fun. Fun matters.
Getting good is good. Those things are all good. It’s nice to be full and it’s nice to have a big vocabulary. It’s just that you’re more likely to eat more if you focus more or less totally on making and procuring tasty food than “efficient”, “filling” food. Similarly, if you focus just about exclusively on having fun through the language, while you still suck, while you’re not full yet, you’ll naturally “eat” more of it, and eat more often, and naturally get “fuller” faster.
-Khatzmuto, Why Don't You Learn Like You Eat?, emphasis original (content warning: this article is clean, but if you browse his site, be aware he's sometimes rude, and occasionally pretty crude)
We watch a couple of Japanese Minecraft channels, sometimes just for passive exposure, sometimes I harvest sentences for the kids, sometimes I keep my dictionary close as we're watching so we can look up words that are said.
This one is good for just putting on as background noise, so that we can listen all morning:
Japanese Language Books:
You can get a surprising amount of Japanese books, especially Japanese-English bilingual books, and Japanese editions, but also Japanese picture books, from just the regular Amazon.com. Amazon.jp, once you get an account, can be set up so that the interface is in English. Sometimes, I can find them at the local Half-Price Books store, which is great. Having books helps us to become more fluent. It helps us to get used to handling them (some are printed opposite the way that English ones are), and to seeing the kanji and kana. It encourages us to read, which helps our vocabulary to grow. All the things that help with literacy and fluency in your first language do the same things in your second language: books are worth the effort to find.
In addition to books, the Church has a large amount of content available in Japanese. We have a Japanese Children's Songbook that we use, I read part of my scriptures in the Japanese Book of Mormon - the regular app for the phones has it, and it will read to me. I've got a Bible as well, but it's more difficult to read, and doesn't have the audio, so I'm doing the Book of Mormon first. And General Conference is translated into Japanese as well.
Hiragana chart w/ stroke orders
NHK Easy Japanese
NHK for School
Simple Grammar Introduction
Speaking-Japanese.com (Breaking into Japanese Literature)
Tae Kim's Guide to Japanese Grammar
Tae Kim's Facebook Group