The default scrollbars are unusable on touchsreen - it is close to impossible to hit them. I know it may be controllable from css, but this will be so common problem for all touch-screen-friendly applications that I think it should be controllable easily and directly from the code. For list/tree views I've found no way to control scrollbar size. A standalone scrollbar can be sized, but I tried to create a huge (very wide) scrollbar and it works and looks good except for the inc/dec buttons which are still the same size - I think they should by default adjust their size according to scrollbar width, because the massive scrollbar with the tiny buttons at its ends looks really strange (and the buttons are unusable on touch screen).