I use other apps to practice Japanese and learn grammar, but this app is my go-to for references, examples, and diving in deeper to what I come across elsewhere or in conversation.
Every entry has an enormous amount of info, and there are endless example sentences ranging from simple to quite complex, which I find very useful.
The organization tools are fantastic as well — nested, organised bookmarks, and categorisation by JLPT level are just two awesome features.
Very highly recommended for anyone learning Japanese!