BunBun - Context Sentences Review App

[davesters81]

皆さん、こんにちは

So, I been working on a small mobile web app in my spare time for something I wish existed, but couldn’t really find anywhere. It’s still pretty fresh and has bugs, but it mostly works so thought I would share it early and maybe get some feedback. It is meant to be run on a phone, so the UI might not look as good on a desktop.

The app is called BunBun (文文). It lets you review context sentences for vocabulary that you have already learned on WaniKani. You can review as many sentences as you want to and you can indicate if you got the reading correct or not and it will track some basic stats. There are also AI breakdowns of all the context sentences, which gives you definitions of each part, grammar notes, and other random general notes about the sentence.

You will need to pass in your WK API token of course, but it only needs a read-only token. It does not write anything back to WK.

BunBun - WaniKani Sentence Review

Here are the basic features that exist currently:

• Daily review sentences queue
• Bookmark sentences
• Intro tutorial on how to use the study tab UI
• Search through all sentences
• Toggle furigana for kanji
• Set maximum JLPT or “difficulty” level for daily reviews. Difficulty is set by the AI based on various factors.
• Set minimum Kanji level for the kanji that appear in sentences
• Stores everything locally, so it mostly works off-line. AI breakdowns won’t work offline tho unless they have already been cached locally.
• Light and dark theme
• Links back to WK kanji and vocabulary pages.
• Tracks some very basic stats so far.

I know it may be pretty buggy, but right now I am looking for general feedback, suggestions, thoughts, etc. Stuff like that. I think the best feature is the AI sentence breakdowns. I find them really helpful. Here are some screenshots of how it looks:

Dashboard

Study Tab

Bookmarks Tab

Sentence Breakdown view

Anyways, I hope you all like it. Let me know what you think!

Update: I forgot to add the link LOL

BunBun - WaniKani Sentence Review

One last quick note for those interested: I made this almost entirely with AI. A combination of Gemini and Claude for the code, and UX Pilot for the UI designs. Using the Antigravity editor.

[hydrogen-2]

This is very cool and something I’ve wanted to build myself. As a professional software engineer, I’m amazed you were able to do that with AI.

[inisfail]

Once I figured out how to adjust the sentences to only N5 level, it was very helpful. Love the advanced breakdowns!

I haven’t been able to get the audio playback to work yet. Using it as a homepage web app on iPhone 12 with iOS 26.3.1. Tried switching the phone off silent mode. No luck. Any possible fixes?

[davesters81]

Thank you! I’m also a software developer. I definitely had to give it a lot of direction and know what to tell it to do, but it wrote about 99% of the code. Definitely worth a try if you haven’t messed with Claude code yet.

[davesters81]

Hi there, thanks for trying it out! The audio playback just kind or worked for me on Android, but I tried it on iOS just now and it doesn’t work for me either. So I will take a look at it and see if I can figure out why.

[jivx]

Nice work shipping this — the AI breakdowns for context sentences are a really smart feature. Love seeing more sentence-focused tools in the ecosystem.

I’m building something in the same space but from the opposite direction. BunBun helps you understand sentences (reading), while JIVX focuses on producing them — you
get an English prompt, write the Japanese yourself, and AI grades it. Reading comprehension and production are different skills, and I think tools that train both
directions are what learners need.

Would be curious to hear how your users are interacting with the breakdown feature — that’s an area I’ve been thinking about too.