1. A method comprising: enabling an inviter game client to check for current running of an inviter messenger client in a same operating system, on initiation of the inviter game client and connection of the inviter game client to a remote game server; enabling the inviter game client to send, based on an affirmative result of the check, an operating system message to the inviter messenger client that causes at least one game state message to be sent from the inviter messenger client over a network to a messenger server that forwards the at least one game state message to an invitee messenger client, wherein the at least one game state message indicates that the inviter game client is currently active in a particular game, and is sent from the inviter messenger client executing separately from the inviter game client; and enabling at least one field of data in an invocation message that is used by the invitee messenger client for sending to an invitee game client to initiate joining the particular game, a content of said at least one field of data being provided by the remote game server to the inviter messenger client for inclusion in the at least one game state message, wherein the at least one field of data enables the invitee game client to be invoked that is associated with the invitee messenger client and further enables the invitee game client to initiate joining the currently active particular game to which the inviter game client is joined, and wherein the at least one field of data includes a link to be presented if the invitee game client is not installed.