11" laptop may be accompanied by a 23" monitor, while a 5 inches smartphone may be used with a 10 inches tablet. Not long ago only one operation system used to be popular, used on relatively same screens. Now there are at least four platforms (Windows Desktop и Mobile, iOS, Android and MacOS) with wildly waried devices. Users of each have their diverse skills and expectations, while the platforms themselves have different interface elements. We can either adapt one sole interface for all the platforms, or create a separate design for each.