Methods, systems, and apparatus are described for transferring application data. In one aspect, a method includes causing, by a first component on a first device to establish a wireless connection with a second device; receiving, from a second component on the second device, data specifying one or more applications that are installed on the second device and supported by the second component, each of the applications being separate from the second component; determining, by the first component, that a first application installed on the first device matches one of the applications installed on the second device, the first application being separate from the first component; receiving, by the first component, first application data from the first application; and causing, by the first component, the first device to send the first application data to the second component running on the second device using the wireless connection.