I passed N5 (2016) and will sit N4 in December 2018.
New Nihongo 500 N4-N5 (with English and Vietnamese Translation) This is a diagnostic for working out strengths and weaknesses in kanji, vocab and grammar.
READING
I am using JLPT Speed Master N4 Reading Comprehension
LISTENING
I am using 新完全マスターJLPT N4 Listening
My friend passed JLPT N4 July 2017 with Preparatory Course for the JLPT N4 Listening
GRAMMAR
I have just completed Genki 1 and Genki 2.
For grammar revision, I have these (but I haven’t started using them yet): 新完全マスター JLPT N4 Grammar
and TRY! N4
For JLPT N5, I used TRY! N5 and found it very helpful. I have never used 新完全マスター series books before (but my friend passed N4 last year with it).
KANJI
Like most WK users, kanji is the least problematic.
Kanji Master N4
I will practice mock questions for the kanji section (see below).
JLPT N4 Mock Questions
Tanki Master Text for Japanese Language Proficiency Test N4 The N5 version was easier than the actual exam.
Nihongo noryoku shiken yoso mondai-shu - level N4 with CD The N5 version was as difficult as the actual exam.