There are 9 tap zones of the screen, tapping of each of them can be flexible set for any function (Scrolling, opening files, jump to chapters, menu display, and so on) It's possible to manage brightness of screen's lightning by swiping
your finger along the left side of screen.
A number of years ago, I remember using charts that asked you to find your height
along the
left side and then slide your
finger to the right to see your «ideal weight» from choices listed under small, medium, or large «frame» sizes.