Updated August 4, 2026

What is Moji - Learn Japanese Daily?

Moji - Learn Japanese Daily for iPhone is a Japanese vocabulary and kanji study app built by Huy Bui, an independent developer. It was released on May 7, 2026, runs on iOS 18.0 and later, and is listed on the App Store under ID 6760421124. Its official website is moji.study. The app schedules every review with the official FSRS-6 spaced repetition algorithm and teaches from a single hand-curated catalog of 7,435 words, each one tagged to a JLPT level from N5 through N1. There is no account, no server, and no cloud sync: the catalog and your progress live on the device.

If you arrived here trying to work out which “Moji” this is, the short version is at the bottom of the next section. There are several Japanese apps with similar names, and this one is the English-interface study app by Huy Bui.

What the app actually does

You study one card at a time. Tap to flip, swipe right if you remembered the word, swipe left if you did not. That two-button grading is the whole rating system, and it is a deliberate simplification of FSRS-6, which supports four grades. Fewer buttons means faster reviews and no time lost second-guessing whether a recall was “hard” or “good”. The scheduler runs the official FSRS-6 formulas with all 21 parameters (w0 through w20) at a 90% target retention, and it serves everything that is due, with no daily review cap. The full explanation lives on /fsrs, and the way the app visualizes memory strength is covered in /memory-bands-retrievability.

Around the flashcards sit the rest of the app: an adaptive JLPT-aligned placement test, quizzes (vocabulary, listening, cloze, weak words), kanji and kana writing practice with stroke-by-stroke feedback, Sentence Build for arranging chunks into sentences, a free Daily Mix that blends the modes and ends with writing, on-device Japanese conversation practice that runs locally on the phone with nothing sent to a server, plus home-screen and lock-screen widgets for due cards, streak, and lifetime learned count. Every entry carries a curated example sentence, 7,029 carry pitch-accent annotations, and 5,300 kanji words carry hand-written mnemonics.

The free tier covers the entire comprehension path: flashcards with mnemonics and example sentences, kana writing, vocabulary and kana quizzes, and the Daily Mix. Moji Premium, $4.99 per month or $29.99 per year, unlocks the focused practice modes: listening, cloze, weak words, kanji writing, and the full quiz library.

Is Moji the same as MOJi辞書 or Mojidict?

No. This is worth stating plainly, because “moji” (文字) simply means “characters” in Japanese and several unrelated apps use it.

MOJi辞書, also published as Mojidict, is a Japanese-Chinese dictionary suite made by a different company. It is a dictionary product for Chinese-speaking learners of Japanese. It is not related to this app in any way, and neither team is involved with the other.

“Moji - Learn Japanese & Kanji” is a separate iPhone study app published by a different developer under a similar name. Also unrelated.

Both are legitimate products serving their own users. The point here is only identification, not comparison. What identifies this app:

If the app you are looking at is on Android, has a Chinese interface, or is published by anyone other than Huy Bui, it is not this one.

How it is built

The dataset starts from public sources and is then curated by hand. JMdict from the Electronic Dictionary Research and Development Group is the dictionary base. Frequency data derived from JPDB determines the study order. KanjiVG supplies the stroke-order data behind writing practice. Attribution for all three is included in the app under Settings, Credits.

None of that is shipped raw. Meanings are rewritten down to at most about three friendly glosses of 30 characters or fewer, with the parenthetical noise that dictionary entries carry stripped out. Usage notes are written only when there is a true, non-obvious, actionable fact to state, which is why 5,698 entries have one and the rest deliberately do not. Example sentences for the first 600 words are written to a strict difficulty budget, so an early card almost never asks you to read past more than one unfamiliar word. Retired entries go into a tombstone ledger rather than being deleted, so a catalog update never silently erases a learner’s progress. The full account of the standards and the review passes is at /how-we-curate-japanese-vocabulary.

The study order gets the same treatment. It is frequency-derived and then hand-edited, which is how core particles end up front-loaded: は (wa, topic marker) enters around position 63, が (ga, subject marker) around 89, か (ka, question marker) around 109, and を (o, direct object marker) around 129, each introduced with example sentences chosen to show where the particle sits in a sentence. That reasoning is unpacked at /why-word-order-matters.

Timeline

Moji - Learn Japanese Daily launched on the App Store on May 7, 2026. Development since then has been continuous and incremental, shipped as regular App Store updates rather than milestone releases. The most substantial scheduling change so far came in August 2026, when the daily review cap was removed and the scheduler began serving every card that is due. The reasoning behind that decision, including why the cap seemed like a kindness and was not, is written up at /why-we-removed-the-review-cap.

Philosophy

Small, focused, and iPhone-native, with quality preferred over volume.

Small and focused means one curated deck instead of a deck marketplace, one rating gesture instead of a configuration screen, and a feature list that stops well short of “everything”. Moji does not try to be your grammar course, your reading platform, and your tutor. It does vocabulary and kanji, and it expects to sit alongside other tools. If you are assembling that stack, /after-duolingo-japanese is an honest map of what goes where.

iPhone-native means built with the platform rather than wrapped in it: widgets on the home and lock screen, on-device conversation practice that never leaves the phone, and a design that behaves like an Apple app. That is also the constraint. There is no Android version and none is planned, because one developer maintaining two platforms would mean doing both worse.

Quality over volume means the catalog is 7,435 words and stops there. Every meaning, example sentence, and mnemonic is written and reviewed by hand rather than bulk-imported. A larger number would be easy to produce and would make the App Store listing look better. It would also hand you entries nobody checked, and finding out which ones those are is your time, not ours.

Read how it works

Every claim above has a page behind it:

• /method, the one-screen map of curation, ordering, scheduling, and sentences
• /fsrs, why FSRS-6 rather than SM-2, and what 90% target retention means
• /how-we-curate-japanese-vocabulary, sources and standards for the catalog
• /why-word-order-matters, frequency ordering and front-loaded particles
• /example-sentence-difficulty, the one-untaught-word budget
• /kanji-mnemonic-method, the component-hook mnemonic format
• /how-many-words-for-jlpt, per-level word counts
• /anki-alternative-japanese, an honest comparison including where Anki wins

Contact

Questions, corrections, and bug reports go to support@moji.study. Corrections to the catalog are genuinely welcome; a wrong gloss is a bug.

Moji - Learn Japanese Daily is free to download, and the comprehension path stays free with no time limit, so you can see whether the approach suits you before deciding anything. Download Moji on the App Store

Sources

• App Store listing, Moji - Learn Japanese Daily, App Store ID 6760421124.
• JMdict / EDICT, Electronic Dictionary Research and Development Group, https://www.edrdg.org (Creative Commons Attribution-ShareAlike 4.0).
• KanjiVG stroke-order data (Creative Commons).
• JPDB-derived frequency data.
• FSRS-6 algorithm, Open Spaced Repetition, https://github.com/open-spaced-repetition