The distance measurement is a feature that can be accesed by Open left main menu → Measure. After clicking on this function a cross hair in the middle of the screen is displayed. On the right side of the screen there are three icons:

• Trashbin - deletes last point in the measurement line
• Plus - to add point which will be in measurement line. After tapping on this point, the point where the cross hair is currently will be added into the measurement.
• Arrow - replaces last point of measurement with current point.