The intent of the library is to help you design, pitch, and build amazing applications. We've focused on balancing ease-of-use with accuracy - while some aspects aren't 100%, they are made to be reusable by reducing them to the minimum number of layers. The core components to the right attempt to cover as many of the common UI elements within the OS as possible, including vector renderings of the phones themselves. Below that are operating system level screens that are common outside of individual app experiences. And at the bottom of the page are flows through common apps for reference and use.