The columns of symbols in the beige Tablature-Sheet at the center of the app’s main screen are actually Shakuhachi Notation. The tablature/score is read from top to bottom, right to left. (By default, there’s a moving red circle to indicate the current note — this can be turned on/off from the main-menu.)
Each of these columns is numbered in Japanese; but that can be switched to western numbering, also from the main menu.