I don’t know if it’s a recent update or it took me a while to notice, but the Android Kindle app now supports JP-EN for bilingual dictionary entries with full example sentences that are easy to copy and mine for flashcards.
To change the default monolingual entries, long tap a word and press the dictionary title tab next to the blue text ‘go to dictionary’ at the bottom of a definition box. Select 日本語・英語 , wait for download and you’re done. It’s based on the shogakukan progressive 和英中辞典 which seems to have an extensive corpus even though it cannot really deconjugate verbs.
It’s a great function if like me you’re at an intermediate level of Japanese and the amount of unknown words in the monolingual definitions can sometimes look overwhelming.
Sorry if this info is obvious for some people but I swear I did not find out about this until now and it has improved my reading experience on Kindle app immensely.