The easiest level is N5 and the most difficult level is N1. Corresponding to this,the APP of JLPT Vocabulary (Pronunciation Edition) include N5~N1 five series. This app contains 610 basic vocabulary of the JLPT N4. All the words with the Japanese pronunciation,sound clear and pure. It will be a good choice for Japanese vocabulary learning. Hope this App can help you happy to learn Japanese Vocabulary.