The Mobile Application Builder for Zimbra Community makes use of Remote Studio Widgets, a feature of Zimbra Community 8.0. Almost all of the user experience is implemented using Studio Widgets and can be customized using the same techniques used to customize Zimbra Community 8.0.
The Mobile Application Builder defines a basic user experience framework consisting of a header, content, and navigation region in which widgets are placed to implement applications.
The header is defined by the user experience framework. (This, itself, is not a widget.) Widgets can use the client API to define links and header behavior to implement actions on individual pages of content.
The content area renders all non-navigation pages (for forum thread list in the screenshot above). Each page is defined by a <page> node in a common configuration file and can contain zero or more configured Studio Widgets.
The navigation area (area with a dark background in the screenshot above) is a special page that is used to define the content of the navigation area. It is a page named "navigation" in a common configuration file and can contain zero or more configured Studio Widgets.