Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for receiving first user input, the first user input indicating a first intent; searching applications installed on the computing device based on the first intent; determining that none of the installed applications are capable of fulfilling the first intent; transmitting a request to a server system, the request requesting applications capable of fulfilling the first intent; receiving a list of one or more applications, each of the one or more applications being capable of fulfilling the first intent; downloading and installing a first application of the one or more applications; launching the first application; and fulfilling the first intent using the first application.