The best!
Why not get it? It’s free and it’s the best! I have the So-matome N3 kanji book and this is making it so much easier to learn! I love the Genki book apps for kanji as well and this is the only app that matches it in quality! Definitely recommend. The only downside to the app/ book is it doesn’t provide the meanings for each kanji individually. Only readings and common vocabulary for that kanji. If they could add meanings to each kanji that would be great! But it doesn’t take too much time to look up the meanings for the kanji on your own.