Works fully offline

A Japanese trainer that lives in your pocket

A dictionary with tens of thousands of words, pitch-accented conjugations, spaced-repetition testing and Genki grammar – no internet, no ads, no Google Play.

Download APK See what's inside ↓

version 1.9.1581 · 54.1 MB · Android 8.0+

N5–N1JLPT levels
100%works offline
Freeno ads
Never forget spaced repetition (SM-2)
音声pitch accent
N5–N1all JLPT levels
100%works offline
4learning sections
Freeno ads or subscriptions
Features

Four sections that build on each other

What you look up in the dictionary, you can immediately practice in the test – and back again. Below is a showcase frame for real app screenshots.

Screenshot of the Dictionary screen: word list with part-of-speech, conjugation group and JLPT level badges

Dictionary

Verbs, adjectives, nouns and kanji with full conjugation tables, pitch accent and kanji composition.

Screenshot of the Test screen: a verb conjugation question card with an answer input field

Test

Conjugation, vocabulary and grammar – typed or multiple-choice, spaced repetition (SM-2) keeps what you've learned from fading.

Screenshot of the Grammar section: a Genki article with the construction formula and examples

Grammar

A reference built on Genki I–II, with formulas, examples and translation practice with answer checking.

Screenshot of the Reader section: text at a JLPT level with a highlighted word and its popup mini-card

Reader

Texts by JLPT level – tap any word for an instant card with its meaning, reading and furigana.

Screenshot of the kana table: hiragana godzyuon grid with romaji Screenshot of the radicals reference: kanji keys grouped by stroke count Screenshot of the counters reference: counter suffixes with reading changes

References

Kana tables with playback, all 214 kanji keys grouped by stroke count, and counter suffixes with their reading changes (一人 – hitori, 二人 – futari) – built in, no separate app needed.

Installation

Download and install in four steps

The app is distributed directly – the server serves the file with resume support and a signature to verify integrity.

JCore 1.9.1581 2026-09-05 · 54.1 MB · Android 8.0+
sha256 (file integrity check) 2e7f6a283652a42e65786ff2c81d4a4aee9c0bac0d65d5400da4adc8010636ba
Download APK
1

Download the APK with the button above, using your phone's regular browser.

2

“Install blocked” is normal for an APK outside Google Play. Allow the source right in that same dialog.

3

Play Protect may ask whether to scan the file – it's safe to choose “Install anyway.”

4

Open JCore – the dictionary is already built in. The app finds and downloads updates itself.

Data

What the app does with your data

The dictionary, test and grammar work fully on-device – no internet required.

No ads, no analytics SDKs, no trackers.

Signing in with Google is optional – it's only used to sync favorites between your devices.

Your data is never sold or shared with third parties.