KanjiBuilder is a kanji building game inspired by exercises found in a textbook called "漢字・語彙が弱いあなたへ". You are given a reading and meaning of a kanji, and you must "build" it by selecting the correct kanji parts it is composed of.
Other game modes include:
* jukugo (compound word) builder, where you are given a part of a jukugo and the reading and meaning of it, and you must select the correct kanji that comprises the full jukugo.
* jukugo kanji parts builder, where you are given a part of a jukugo and the reading and meaning of it, and you must select the correct kanji parts that comprise the missing kanji of the full jukugo.
* single-reading phonetics: you are given a phonetic, its reading, a part of a jukugo and its reading and meaning, and you must select the correct kanji part(s) that together with the phonetic comprises the missing kanji of the full jukugo.
* mixed-reading phonetics: same as above, but these phonetics have multiple possible readings, not just one.
* lookalikes: you are given a reading and meaning, and you must select the correct kanji among all the similar-looking kanji.
You can limit the span of the kanji generated to a specific school grade (from 1st grade of primary school up to high school); to a specific JLPT level (N5 to N1); or to a specific KanKen level (10 to 2).
There are both practice and test modes available with hints. You can also choose to decompose and build kanji with either 2 or 3 parts.
You can further limit the scope of the generated kanji/jukugo in the full version of the app, which includes limiting up to/down to a certain school/JLPT/KanKen grade/level, and also up to James Heisig's Remembering the Kanji (RTK) index (4 to 2195). The full version also features no ads. Link: https://play.google.com/store/apps/details?id=com.kanjibuilder