I advise to use Japanese dictionary with Coolreader. The Coolreader from here
https://www.mobileread.com/forums/sh...d.php?t=256917 can correctly work with Chinese hieroglyphs. So it can combine many Japanese hieroglyph words too.
P.s. What do you think should I add to my hiragana keyboard some most frequently used kanji? For example 日一国会人年大十二本中長出三同時政事自行社見月分. May be you want to offer your kanji list?