The App Studio markup language defines a set of HTML-like elements, or tags, for defining search queries to the backend and visualizing the search results and facets, handling all the complexities of connecting to Fusion. For example, adding a radial progress bar is as simple including the following tag: 
<progress:radial
    percentage="56">
</progress:radial>
This results in the following: Radial progress bar tag Over 150 tags are provided in the Appkit framework.