There are tons of study materials in book stores, in the Web and available as Apps, that claim to cater for the JLPT N4 test, but is there any reliable source for what is really required for N4 (or N3-N1 for that matter) ? Study for N5 was easy, as it starts from zero, but all next levels seems to be floating somehow and many require quite different vocabulary and Kanji than others for the same levels. According to your experiences, what are the closest sources to actual N4 requirements for meaningfull and efficient study purposes ?
For me, it worked to complete みんなの日本語初級 II (Commonly referred to as "Minna no nihongo 2") in terms of grammar and vocabulary. I just learned all of the vocabulary words for and the grammar points for each chapter, completed the exercises and I did well in the N4 exam.
As for the Kanji, I can't answer your question because my approach is to learn the kanji for any new word I learn, which is overkilling as regards N4 kanji requirements.