1. A method comprising: receiving, at a first computing device from a second computing device, a request for a view of a user interface of a native application executing on the second computing device, wherein the view includes one or more first user interface components; determining, by the first computing device, a user agent type of the second computing device; selecting, by the first computing device, one or more second user-interface components to be included in the view based on the user agent type of the second computing device; generating, by the first computing device, code implementing a structured document that represents the view, wherein the structured document comprises the one or more first user-interface components and the one or more second user-interface components; and transmitting, from the first computing device to the second computing device, the code.