MentalQuiz is a free iPhone app designed to help users develop positive mental habits through daily quizzes and informative articles. Developed by Kousuke Unno and supervised by Dr. Higashi, a psychiatrist at Shiokai Hospital, this app aims to provide users with a simple and effective way to cultivate a healthy mindset.

The app sends users notifications at their specified time, reminding them to play the daily quiz and read the accompanying column. By answering a few questions and gaining insights from the articles, users can gradually develop a positive mental routine.

Please note that MentalQuiz is the free version of the app, with the only difference being the number of quizzes available. For those looking to explore more topics and have access to a wider range of quizzes, the paid version is available.