The bad reviews people give apps is hilarious to me (although obviously not to the developers). Do these people really think they can go buy books that give you 1/10 the information you get here, plus the fact that there is no interactivity with books, and get said book(s) for like $5? Please. There are no perfect apps, everyone looks for certain things, but come on, just because a few of the things you want to see aren't included, doesn't mean that this isn't still a very, very good learning resource.
Personally, for the example sentences, I would love to see all parts be selectable. So I can break down different parts, and get the fullest definition as well as see how multiple kanji phrases fit together as part of the larger context. This would be awesome for me (I've seen this available in Japanese by codefromtokyo). But just because this feature isn't available here yet (hint hint, wink wink), doesn't mean that this isn't still a very, very good app; because it is.
If you think you can buy a book that offers what this app does, testing you and giving you the results, showing you how to draw each kanji, and then testing the same with immediate feedback, giving you flashcards used in a spaced repetition format, etc., then good luck. Let me know how that works out for you.