Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
혼천의를 사용하여 별의 위치를 측정할 수 있습니다.honcheonui-reul sayonghayeo byeol-ui wichi-reul cheugjeonghal su itsseumnida.You can use the celestial globe to measure the position of stars.