Presence channel queueing

app.js

var pusher = new Pusher(PUSHER_KEY, { authEndpoint: 'pusher_auth.php' });

// use three channels, one for users waiting in the queue (waiting)
// another for users connected to the TV (control)
// another for sending messages to a specific user (user)
var user = pusher.subscribe('user-id'),
    waiting = pusher.subscribe('presence-screen'),
    control = pusher.subscribe('control');

waiting.bind('pusher:subscription_succeeded', function (members) {
  queue(members.count);
});

control.bind('pusher:member_removed', function (member) {
  queue(waiting.members.count);
});

function queue (count) {
  if (count < 1) {
    var isNextInQueue = null; // you'll need to find out where in the queue you are by calling to you app server 

    if (isNextInQueue === true) {
      waiting.unsubscribe();
      // render control UI      
    }
    else {
      return;
    }
  }
  else {
    // keep waiting
    return;
  }
}