1500 Essential Vocabulary for the JLPT N4

Good for learning vocabulary everywhere

It's a great and small book if you want to improve your vocabulary wherever you go. One of it's greatest strengths is that you can read an example sentence and the translation of the word you're intended to learn, the examples use differences uses of N4 grammar so you can have that references, and if you don't know the grammar used, you can always check it on a book or Youtube and return to the word. I'm learning a lot of grammar and vocabulary with that method.