乙種第4類 すいーっと丸暗記ノートver.2 is an Android application developed by TOOLBOX. It is a free app that accompanies the book, "(Revised Edition) Pass the 4th Class Dangerous Goods Handling Personnel Exam in 10 Days! Easy Memorization Notes" published by TOOLBOX. The app is designed to make the memorization notebook included in the book more accessible to its readers. With the app, users can tap on the damaged parts of the notebook to reveal the answer.

This app's content is in line with the book, so it can be used as a supplementary material for the book. The app is user-friendly, and it is an excellent tool to help readers prepare for the 4th Class Dangerous Goods Handling Personnel Exam.