To navigate between sheets, use the sheet navigation panel below the current worksheet. Tap the necessary sheet tab to switch to the sheet.
To navigate between sheets, you can also tap the 
icon in the bottom left part of the sheet navigation panel and choose the necessary sheet.
To scroll a sheet, swipe up or down, left or right.
To zoom in a sheet, use the stretch gesture: place two fingers on the screen and move them apart.
To zoom out a sheet, use the pinch gesture: place two fingers on the screen and move them together.