Kakugo (f-droid version) 1.37.1

Kakugo is an application that helps learning Japanese. It includes multiple
tests to memorize hiragana, katakana, and kanji and adapts to the user's
learning pace.

One of the biggest difficulty with learning Japanese is memorizing kanji
and vocabulary. While learning them by just reading and writing them
everyday may work, the more kanji you know, the harder it gets and the more
time it takes to revise them all. Proper tools can help you memorize these
huge amounts of knowledge to more quickly become a fluent Japanese speaker.

Kakugo is one of these tools. It helps learning and revising kanji and
vocabulary in an efficient manner. It uses Spaced Repetition in a unique
way that adapts to the user's pace. If you only have time to revise 30
kanji every day, or if you can revise as much as 100 kanji every day,
Kakugo will adapt and test you on the right kanji at the right time for you
to memorize them. There is no "kanji of the day" list to revise, you can
start and finish a session whenever you feel like it.

Kakugo also features a wide variety of tests to help you find the best ways
that will help you learn Japanese.

Features include

* Hiragana, Katakana quizzes
* Kanji quizzes by reading and meaning
* Kanji test by part composition
* Kanji writing test
* Vocabulary quizzes by reading and meaning
* Unique spaced repetition formula that adapts to your own learning pace
* Unlimited quiz sessions that allow you to take a quiz at any time, for however long you want, useful to efficiently spend commuting time
* Show similar-looking kanji in answers to teach you the differences
* Kanji and vocabulary sorted by JLPT level
* Clicking on kanji opens aedict3 (a non-free Japanese dictionary) or jisho.org
* Optimized tablet support
* Open source
* No ads
* No internet access required
* Supported languages: English, French
* More to come

Credits

* The kanji quizzes are based on kanjidic.
* The vocabulary quizzes are based on JMdict.
* The kanji similarity database comes from minerva-access.unimelb.edu.au/handle/11343/35336 and lars.yencken.org/datasets/phd/
* The kanji composition and drawing database comes from KanjiVG.