An app for browsing and learning the billiard cushion system. Among the cushion systems, we are collecting systems that are likely to be used frequently in pocket billiard games. You can learn each system in a quiz format. The billiard table diagram shows the start and finish positions, so use the system calculations to answer the correct number. Questions of various patterns are randomly asked, so you can learn the cushion system efficiently. The quiz has a challenge mode that aims to answe