Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for sending a request, by a first computing device and for receipt by a second computing device, that the second computing device send data that describes characteristics of the second computing device. Receiving, from the second computing device, the data that describes the characteristics of the second computing device. Determining whether the second computing device includes the first component model based on the received data. Determining whether the second computing device includes the second component model based on the received data. Generating, by the first computing device, a graphical user interface that is associated with the second computing device.