I’ve gotten into reading Japanese books a lot more recently, and I prefer e-books as their built-in dictionaries are a god-send for foreign language learners.
I’ve only used Google Play so far. The integrated dictionary is fine, but one annoyance is that it can’t detect any word that uses furigana. Are Kindle, Kobo, or any other platforms any better?
I’ve never noticed it struggling with those either. Obviously, it’s not like I’m paying a lot of attention all the time. I use my Kindle for reading for fun, and occasionally look up one or two words I don’t know, but I’ve never noticed it struggling with conjugated verbs, because it usually just detects the verb’s stem and looks that up. It’s a pretty good detection algorithm in my experience.