It'd be kinda cool if when you shift + hover (or something) over a particular kanji on a sentence flashcard it pulls up that kanji's meaning/mnemonic . I like to remember words based on their kanji "meanings" but sometimes I forget the kanji meaning.
I have the yomichan chrome addon so I get something like this anyway, but it'd be nice to remember the kanji's nativshark meaning rather than the jisho meaning.