Component Designer - is a powerful WYSIWYG tool included in Tizen Studio for layout markup and widget theming. All Tizen native UI applications use EFL as a fast and effective solution. It provides a set of predefined widgets with the ability to create new markups and ways to customize Graphics UI. The EFL "layout" library utilizes its own markup language - EDC that is used for theming of the predefined widgets. It is flexible to create high quality applications, but also complicated and difficult to learn. To make the development process easy we present a convenient WYSIWYG tool for EDC markup and widget theming, Component Designer, which already included in the Tizen Studio. This topic will explain the key points of EDC and describe how easy it is to create UI with Component Designer, including the benefits over EDC.