I don't really have experience but I think you can't get fluent with just using this app because to become (near) fluent you also need a lot of listening/speaking practice and more grammar explanation which you can't get here. But with this app you should be able to learn a lot of vocabs and it's also good for practicing what you have learned. So it's better if you have more than one resource to learn Japanese.
I'm pretty biased, as I run renshuu, but I do not think there is a single textbook, tool, class, app, or anything else that can be the sole provider of "fluency" - as ぱとぱと put - renshuu is a single tool, and while I strongly believe that renshuu offers a much wider range of materials/features than anyone else, it can't cover it all :)
I must say, this app can provide you many things like vocabulary, Kanji writing and others stuff. But it only support you to learn, not like it can teach you anything.
With all due respect, it absolutely can teach things - we are closing in on over 100 Japanese lessons (Resources > Japanese Lessons) that are written in a casual, textbook style by a Japanese professor to teach your Japanese from zero.
I definitely think Renshuu helps learning Japanese to fluency! I spend about 30-60 minutes a day on just Renshuu and have learnt to recognize about 2000 words so far, usually I will see a word in a book and will be like ‘oh I’ve seen this before’ and then see it on Renshuu and it really cements my knowledge. Or I see a word in a book and wonder what it means, then see it on Renshuu and be like ‘oh that’s the word’ I’d attribute about 90% of my Japanese from doing Renshuu and immersion. I also think Renshuu is the best app to learn Japanese effectively and efficiently! As there aren’t distractions, and it’s free!
You’re not going to get fluent from an app. You need to live the language: move to Japan; get a job; marry a native speaker; have kids; send them to school — you still might not be fluent after all that, but at least your kids will be.
In my experience so far it's fantastic for grinding vocab and kanji practice, and comes with probably the most helpful dictionary out there, so it's a wonderful complement to other resources as well. Best part about it has to be how customizable it is, so if you're willing to put in a little work you can make schedules to help solidify external learning too.
I live in Japan, but I'm not fluent at all. To be honest, this app has allowed me to practise and learn a lot on my own. Yeah, I'm still a beginner, but vocabulary is a huge part of fluency. I find that I can use more words in class every week because I learn them here. The listening and speaking, which are vastly more important, are built on a founday of vocabulary and grammar. This is definitely helpful for me.
If so, what your experience?!
