Some praise for the iOS application:

Excellent learning tool. - ★★★★★
A few months ago, I started to learn my Kanji in earnest. Once I learnt the first 1000 Kanji via the wonderful book "Remembering the Kanji" I was eager to learn some compounds. This is where "The Kodansha Kanji Learner's Dictionary" came into play. I simply go through all of the Kanji I have already learnt, find them in this book and then learn the compounds. In conjunction with "Kodansha's Furigana Japanese Dictionary" [...] I then try to use the compounds in sentences. This app is beautifully laid out and easy to search. [...] Great app, highly recommended.
-- SlicerX, iTunes App Store (Australia)

The best - ★★★★★
This is simply the best kanji dictionary app for learners. One needs to play a bit with it to find all it has to offer. I only wish it contained more than the jōyō and jinmei kanji. Except for that, it is perfect!
-- Chafre Gelyon, iTunes App Store (France)

OMG... finally! - ★★★★★
I have the paper version of this dictionary but it had a MAJOR drawback... the use of romaji. I just saw that the electronic version is back [...] and I decided to download it despite no comments/reviews yet. Well... I only downloaded it 5 minutes ago so I have not used it yet... but I browsed through it... and... OMG... Thank you! It can switch readings between romaji and kana. So if you want to avoid (like I do) any and all romaji, you can just check the kana readings and there you go. A great dictionary! Thank you CJKI for having made your dictionary even better!
-- Mirichan, iTunes App Store (Canada)