世界でいちばんやさしい囲碁問題集 (The World's Easiest Go Problem Collection) is an Android app developed by UNBALANCE Corporation. It is a free game in the board game category, specifically designed for those who want to learn Go. The app is supervised by popular shogi players Yukari Yoshihara, Yuito Wang, and Kana Manba, who are known for their expertise in teaching beginners.

The app offers a collection of 540 basic Go problems divided into 20 themes. Each theme includes both explanations and problems. Initially, four themes are available, with new themes being unlocked as you progress. By solving these easy problems, players can naturally learn the rules and basic playing techniques of Go.

In addition to the problem collection, the app also features a "Challenge the Test" mode. As you progress through the problems, you can take a test that consists of 30 randomly selected questions from the problems you have solved so far. This allows you to assess your mastery of the basics of Go.

世界でいちばんやさしい囲碁問題集 also provides clear explanations of the rules of Go, making it accessible even for beginners. With this app, anyone can have fun while mastering Go.