Reading is one of the things I developed my other app, Nihongo, to help with.

I take DRM free ebooks and copy them into the app one chapter at a time. It automatically creates flashcards for all the words that appeared that I don't already know, and I can filter down to only words that appear at least twice.

I pre-study those "essential" vocab, then usually just read without looking anything up. But the app also makes it so you can tap on words to get a quick definition.