sentences:  Device Central provides designers and coders a comprehensive testing facility that approximates how pages and graphics will look on a variety of cell phones with different screen resolutions, color depths, memory constraints, and other performance characteristics.It simplifies the mobile authoring workflow and allows developers to preview designs and test content on the desktop before loading it on the mobile devices for final testing.A library of mobile device profiles on Device Central are updated quarterly, with an initial support for over 200 devices at launch.