Metro Style (Flat design) is a design style introduced by Microsoft. This minimal approach removes unnecessary details in an interface and takes the design down to the core functionality. By including only the elements that are necessary, a designer can create an elegant and responsive easy-to-use interface quickly. Metro Style is a popular web design style nowadays. UI kits offer ready made UI elements, ready to use for a website or app. If you’re not great at design but have the required coding skills, UI kits can be a great way to make your app or website looks appealing.