online on a mobile device

Unfortunately, there is no way to detect if a user is online on a mobile device. In fact, the RC app (desktop, Web, mobile) and WebRTC apps have a dynamic device ids and they are not detectible using the list extension devices API. Even recently, there was a change in the system that API returns the device object of the RC app. But the device id of that device is not the real device id and the status is always "offline".