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