This app was mentioned in 12 comments, with an average of 2.50 upvotes
Human Japanese can be great to use depending on your desired pace. They do an absolutely terrific job of teaching you about Japanese cultural context while you are leaning the language. They also teach stroke order and mnemonics if you need those. There are memory games you can play to practice your character recognition.
Link: https://play.google.com/store/apps/details?id=com.braksoftware.HumanJapanese
They also have a Lite version and an Intermediate version. When I was using it a few years ago, the creator would write e-mail interesting words to learn during the week which showed he was actively behind the app.
I have no complaints about HJ, but for learning at breakneck speeds (outside of an actual Japanese course), Duolingo has been very effective for beginner's fluency. It doesn't teach you how to write or about history/culture so if you have high intelligence or prior experience, you can learn (and retain) the whole course in a month. It's caveats are that there are more errors than HJ and it is certainly as less personal/conversational affair.
Link: https://play.google.com/store/apps/details?id=com.duolingo
I would recommend HJ if you are new to Japanese as it really is a 'cosy' and comfortable way to enter your learning. Once you have a decent familiarity with the language, blaze your way through Duolingo to expand/reinforce what you know.
/r/LearnJapanese is a great resource but not the best to start with.
I recommend finding apps to help you start learning grammar and some basic vocab. The more you immerse yourself in it and the smarter you study the easier it'll be for you.
As far as apps I highly recommend Human Japanese Or on iOS. It is written more like a person would speak and isn't very dry. Yes it is paid but there is a trial version you can use instead to see if it is of any use to you. I also recommend you try a flashcard-type program to help build up vocabulary. Memrise has some good Japanese lessons and Ankidroid has flashcard sets for Kana,Kanji, and Vocabulary plus you can always make your own when you find new words you want to practice.
If you're looking for a more structured app with quizzes and grammar explanations as well as plenty of vocabulary, check out Human Japanese. It's only around 10 dollars.
The first one is about the same content as the first two Japanese from zero books and there is an intermediate version of HJ as well, so it should keep you busy for a while. I'm just about to finish with the first one and start the intermediate one. Apparently, that one teaches you kanji as well. The first one teaches you hiragana and katakana in the beginning and then you get to use it a lot as you work through some grammar and vocab lessons.
There is also a free version with the first 8 chapters and a preview of chapters 9 - 42, so you can see if you like the style first.
I highly recommend the app Human Japanese
https://play.google.com/store/apps/details?id=com.braksoftware.HumanJapanese
It's also on the apple app store and there should be a "lite" version as well that is basically a demo to try out.
Is it really? Pretty sure I learned it in a lesson in the Human Japanese app (this is like 4 years ago when I was studying the language a little bit).
Just tried it out, the minigames are really punishing and not very nice to play for that reason, they 'buzz' you out if you are even slightly off the centre of where it wants you to write. I would recommend Human Japanese instead. Excellent app with a much nicer way of learning. Thanks for the post though, it's made really nicely but the gameplay is flawed.
I intend to learn Japanese too someday. Many sources have recommended this app: https://play.google.com/store/apps/details?id=com.braksoftware.HumanJapanese&hl=en
Duolingo is great for introduction to a language but it only teaches by repetition. There isn't a "guide" you can consult. After a while, when the language becomes more complex, you need a few pointers about which variation of a word goes where and that is sometimes not obvious even if you do trial and error. I started learning French via Duolingo and it make me interested enough to consult a proper textbook as a supplement.
Human Japanese is excellent. They have an intermediate version and free lite versions.
If you don't want to spend money, Duolingo should be your go to. Japanese was added recently too! Excellent for beginners.
If you want to learn a bit of the culture, I found Abroad in Japan YouTube channel quite entertaining. They also have a podcast.
If you can't read hiragana and katakana, find an app for that and learn them right away (really doesn't take long).
You'll want some way to study grammar, and while a textbook like Genki is probably best, Human Japanese or Tae Kim's Guide are good options that I really like.
You'll also probably want a way to learn Kanji, in which case I would pick up a copy of the Kodansha Kanji Learners Course and the Anki app plus related decks. If you want to stay entirely on mobile and don't mind monthly fees, try out WaniKani.
As for vocab, Anki with one of the "Core" vocab decks would be a good start.
You want the app, not the deck:
https://play.google.com/store/apps/details?id=com.braksoftware.HumanJapanese&hl=en
See the 'Similar' section for the Lite version.