Everything you need to get a word from first meeting to long-term memory: picking the right JLPT level, setting a daily goal you can actually keep, and using every study mode the app offers.
AiWords is a Japanese vocabulary app for iOS and Android covering JLPT levels N5 to N1. You pick a word book for your level, study a set of new words each day, and the app schedules your reviews with a spaced repetition system so words come back right before you are about to forget them.
On top of the core loop, every word ships with AI-generated example sentences and audio, and you can study in eight different modes — from multiple choice to handwriting recognition to AI-driven story conversations in Storycast. Core vocabulary study is free; a subscription adds Storycast voice conversations and extra capacity.
Your study records sync to the cloud under your account, so it is worth signing in before your first session. You can register with an email address and password, use Sign in with Apple, or start as a guest and bind an email later from Profile, Account Settings, Email Settings.
Binding an email is worth a minute: it is what lets you recover your password and receive important notifications.
From the home screen, tap Select Learning Book. AiWords organizes vocabulary into books by JLPT level, from N5 (beginner) up to N1 (advanced). Each book shows its word count and a short description, so you can judge the workload before committing.
If you are studying for the JLPT, pick the book that matches your target level. If you are learning for fun, starting one level below where you think you are is a good habit — reviews pile up fast, and an easier book keeps the daily session short enough to finish.
After choosing a book you configure the plan. Three decisions matter:
You can set 1 to 500 new words per day; the app recommends 10 to 50. Be honest here: every 10 new words generate 3 to 5 times that number in reviews over the following days, so 50 new words a day can mean sessions of 20 to 25 minutes at peak.
The review count is auto-calculated as 5 times your new words, and you can override it with any value from 1 to 1,000. If your sessions start feeling endless, lower this number before lowering new words — clearing the review queue is what keeps tomorrow short.
You can change all of this later from Profile, Study Settings, and you can switch books at any time — your progress on each book is kept separately.
Each day, the home screen shows your current book, your progress through it, and the day's queue of new words and reviews with an estimated study time. Tap Start Learning and the app mixes the day's new words and due reviews into one session.
The quick action button on the home screen jumps straight into your most-used study mode. You can pin it to a fixed mode or set it to always open the last mode you used, from Profile settings.
If you close the app mid-session, AiWords offers to resume where you left off the next time you open it — or start over, if you prefer.
During a session you rate each word yourself, and the rating feeds the spaced repetition scheduler:
Hard
You did not know it. The word stays close and comes back soon.
New
You are meeting the word for the first time or it is still unfamiliar.
Seen
You had an impression of it but could not produce it confidently.
Know
You had it. The next review is pushed further out.
There is also Skip, which removes a word from future learning sessions entirely — use it for words you already know cold. In quiz layouts you can simply answer the multiple-choice question; the app derives a quality score from your accuracy if you do not press a rating button.
AiWords tracks active study time per session and per day, and warns you when the daily reset time is approaching (at 30, 10 and 3 minutes) so a late-night session does not accidentally count toward tomorrow.
The reset time itself is configurable in Profile, Study Time settings, along with your timezone — set it to an early-morning hour if you study late.
Going to miss a day? Use the Day Off button on the home screen. It protects your streak for one day; you can take one per day, and it can also be cancelled if plans change.
AiWords schedules reviews with a variant of the SM-2 algorithm, the same family of algorithms behind most serious flashcard tools. Every word you study carries three numbers: an easiness factor, a repetition count, and an interval in days. After each encounter the app scores how well you knew the word on a 0 to 5 scale, updates those numbers, and computes the word's next review date.
If you press a rating button, that choice is used directly: Hard maps to 0, New to 3, Seen to 4 and Know to 5 on the quality scale. If you just answer quiz questions, the score is derived from accuracy — 100% correct scores 5, 80% scores 4, 60% scores 3, and so on down to 0. The number of wrong picks is also sent along, so a word you keep confusing with the same distractor comes back sooner.
Words you know well drift toward longer intervals; words you keep missing stay close, with short intervals and more repetitions. That is the whole trick — the schedule adapts word by word, not session by session.
The server assembles each day's queue from words whose next review date has arrived plus your allowance of new words, and the home screen shows both counts before you start. If a day's queue grows past your daily review cap, the overflow waits for the next session rather than vanishing.
Every plan can be studied in several modes, and you can switch freely from the home screen. Each mode exercises a different direction of recall — recognizing meaning, producing spelling, training your ear — so mixing them makes memory more durable.
See the word in kana and choose the correct meaning. The classic recognition quiz.
Listen to the pronunciation and pick the meaning. Trains your ear, with the kana revealed if you get it wrong.
See the translation and choose the correct Japanese word. The reverse direction — harder, and closer to speaking.
See the translation and type the word, with Japanese IME support. Reinforces spelling. Available for Japanese books.
Write the word's kana by hand and let on-device recognition check it. Available for Japanese books — see the handwriting section below.
Words auto-play one after another with repetition, like a listening stream. Good for commutes and passive passes.
Page through the book freely, with all details visible. No quizzes — use it to scout ahead or look words up.
The classic Japanese study trick: red and green sheets mask parts of each card. Tap a card to hear it, tap a masked area to reveal. Self-test at your own pace.
Handwriting Practice and Type Practice appear only when your current book is a Japanese-language book, since they test kana production.
The same session content can be studied in any mode, so a good routine is one quiz mode for the daily goal, plus Radio or Color Card for an easy evening pass.
Every word in AiWords comes with example sentences generated for that word, each with its own translation and narrated audio. They are written to reflect real situations and cultural context rather than textbook filler, so you learn how a word is actually used, not just what it translates to.
Example sentences play automatically in study sessions, and you can replay the word audio or any sentence audio with one tap. Example content is part of what the subscription expands — free accounts see the core set, while premium unlocks unlimited examples and AI scenario lessons.
Handwriting Practice asks you to write each word's kana by hand, and the app recognizes your strokes on the device using Google's ML Kit digital ink recognition. Writing a word is a stronger memory signal than choosing it from a list, which is exactly why this mode exists.
Storycast is the AI Stories tab: interactive stories where you chat with AI characters and practice your vocabulary inside real conversation scenarios. Each story starts with warm-up teaching cards that introduce the new words, phrases and grammar you will meet, then moves through demonstration, explanation and practice phases.
You can type or, with voice mode, actually speak your lines. After each session you get a report with scores for speaking, vocabulary, grammar and comprehension, plus a Story Article tab that turns the conversation into a bilingual narrative you can re-read.
Chat settings let you show translations by default, keep text visible during voice sessions, and choose whether the app exits automatically after the report. Conversations can be paused and continued later; ending one is final, and the app asks before you do.
Storycast usage on the free plan is subject to limits; voice conversations and higher story capacity come with the paid plans. When voice stories are on a free promotional window, the subscription screen shows the end date.
The Study Statistics screen turns your sessions into numbers you can act on:
All of it syncs to the cloud with your study records, which upload automatically — including when the app moves to the background — and retry locally if the network is down. Sign in with the same account on another device and your progress is there.
Since 3.1, the Profile screen also shows your learning statistics directly: a stats card with your daily numbers, a trend chart, and shortcuts to your study settings and plan history.
The core of AiWords is free and stays free: every study mode, all of your daily words, and full review cycles, with no time limit. The subscription is about the AI extras, not the vocabulary engine.
There are three plans, each adding more Storycast voice minutes and story capacity:
Starter
A daily sip of AI conversation — for casual learners curious about Storycast.
Pro
Immersive voice dialogues and longer stories — for daily learners building real fluency.
Max
Maximum voice minutes and deep story arcs — for serious learners going all-in.
Plans are marked with the community favorite and, on Max, a best-value badge. Prices vary by region and are shown on the subscription screen before you buy.
Subscribe from the Upgrade button in Profile settings or from the subscription screen. If you are already subscribed, the same button becomes Manage. Purchases can be restored with Restore Purchase, and cancellation happens in your Apple ID subscription settings — after cancelling, premium stays active until the end of the period you already paid for.
Subscriptions auto-renew and can be cancelled anytime in iOS Settings. Prices vary by region.
The Japanese recognition model is about 10 to 15 MB and downloads once on first use. It needs a working network connection; if it fails, tap Retry. Recognition itself runs on-device after that.
Word audio streams from the server, so check your connection first. Also check the app's mute behaviour setting — sessions can silence audio playback intentionally. Restarting the app clears stuck audio state.
If an email is bound to your account, use Forgot Password on the login screen to get a reset link. Without a bound email, contact support — binding an email in Profile, Account Settings is the cheapest insurance against this.
Study records sync to the cloud automatically, including when the app goes to the background, with local retries when offline. As long as you log in with the same account, your progress follows you.
Open the subscription screen and use Restore Purchase. If that finds nothing, check that you are signed into the same Apple ID you bought with, then contact support.
In order: restart the app, free up some phone storage, update to the latest version, restart the phone. If it persists, report it from Profile, Feedback with your device model and OS version.
Account deletion lives in Profile, Account Settings. It asks for your password, marks the account for deletion, and permanently removes it after 30 days — contact support within that window if you change your mind. Paid subscriptions are cancelled automatically.
Anything else? Write to us via the support page or email — reports with a device model, OS version and a short description of what you were doing get fixed fastest.
Download AiWords, pick your level, and let the first session set the rhythm.
Download on App Store