OK, Tracy is correct. We had the wrong app. I went looking and found a bunch of info on this thing. Also, I learned a new trick with the iPhone.
From and MSC rep on cruise critic "The MSC Divina Traveller App is only accessible onboard the ship. You don't need to purchase a WiFi package to access and it is completely free. To access the app, just open up a web browser on your smartphone and you will be prompted to login with your Internet ID that can be found on your cruise card."
This app works free with the ships wifi and it has the chat. I don't think it will chime or vibrate, but if you check it once in a while you will get your messages.
iPhone users. Go to settings, put phone in airplane mode, touch wifi, turn it on. You will notice that you're still in airplane mode, but wifi is on. The cellular line with still read airplane mode, but the wifi will connect. The same can be done with bluetooth if you have one of those speakers with you. I feel like a caveman sitting by a fire when another caveman rides by on a bicycle