I normally hesitate to recommend apps that cost money. But VReader is well worth the $3.99 price tag.
When you first open this app, you can choose from a list of popular and classic books, including 1Q84 by Haruki Murakami. You can also import your own ebooks from iTunes.
When you open a book, you can tap a sentence to have the app read it aloud. You can tap individual words and phrases to get definitions in English.
I recommend this for advanced learners who are ready to transition to reading books intended for a Japanese audience.
You can try VReader for free, with access to a limited number of pages per book. VReader is available for iPad or iPhone.