It definitely helps with hiragana and katakana a lot, the quick draw game definitely helps with it and it’s fun! And shiritori is also really good! You can learn so many more words with it!
Renshuu has definitely improved my Japanese, and I'd recommend it over every other study tool I've tried.
I use mastery schedules as my primary method of studying vocab and kanji, and that's where Renshuu's helped my confidence the most; I only knew hiragana and katakana and some basic tourist Japanese when I joined (in 2018 I think), and even after taking several long (1yr+) breaks from active studying I currently have a vocabulary of almost 8000 words and 1500 kanji. I don't personally use Renshuu as much for the grammar or games (even though they're just as good), but since the site has so many resources and ways to study in one app, you can really get whatever you want out of it and use it in whatever way is best for your study style. I think it's got something for everyone.
I've used it as my primary resource for: vocab, kanji, grammar, and listening. (I supplement with extra reading and listening for both enjoyment and sanity)
For me, Renshuu is the best tool out there. It's far more comprehensive than other tools, because it covers vocab, kanji, grammar, and listening, and it integrates them together.
How's my Japanese ?
Definitely better than it was a year ago. Now, I'm at the stage where I can read fun stuff like simpler manga (with a dictionary), and NHK News Web Easy. So, I still feel like I have a long way to go in my journey, but Renshuu still feels like the right tool to get me there.
I've been using this site since 8 months ago, and I've gone from just knowing the kanas to being able to read and understand short novels It keeps me consistent and it lets me review the content I find while reading/watching very easily, which is my main source of learning, though I've definitely learnt lots just from here! I think renshuu's best point is that it's extremely versatile, so even if your routine doesn't look like mine, you'll still get plenty of use of it.
It helped me a lot with memorizing kanji and vocabulary (even though I wasn't really convinced studying kanji outside of words was useful, at first), so that within a year I've gotten from struggling to reading Japanese novels to getting to being able to read relatively fluidly.
It keeps me consistent and it lets me review the content I find while reading/watching very easily, which is my main source of learning, though I've definitely learnt lots just from here! I think renshuu's best point is that it's extremely versatile, so even if your routine doesn't look like mine, you'll still get plenty of use of it. 