1. A method comprising: by a first client computing device, detecting activation of an avatar by a first user, wherein the avatar represents a second user and the avatar is displayed in a graphical user interface of a first application comprising a social-networking application on the first client computing device; by the first client computing device, in response to detecting the activation, automatically sending a request to a server computing device to select a communication channel for connecting the first user to the second user, wherein selection of the communication channel is based on contact information of the second user and current use by the second user of a second application associated with the communication channel on a second client computing device associated with the second user; by the first client computing device, receiving from the server computing device communication-channel information for the communication channel associated with the second application that the second user is currently using on the second client computing device; and by the first client computing device, in response to receiving the communication-channel information, automatically initiating without user input a connection between the first user and the second user by a third application on the first client computing device, wherein the third application is associated with the communication channel selected by the server for connecting the first user to the second user, and wherein the third application is synchronous to the second application.