This is the official app by Ask Publishing. It’s designed specifically for their textbooks. You can search for the N4 Listening or Grammar books within the app and download the audio tracks directly to your phone for free. Why the Audio Matters
After downloading, unzip the folder. You will see tracks named 01-01.mp3 , 01-02.mp3 , etc., corresponding to each lesson’s listening exercises or example sentences. Nihongo Sou Matome N4 Audio Download