seems awesome for recreational and emergency communication
In an emergency, using voice or CW will be heard by a lot more people, and understood by them a lot easier, more reliably, and better than having to have an app on both ends.
Don't get me wrong, it's cool tech (after I figured out what it actually is), but it should not be presented as useful in an emergency. In an actual emergency, the last thing that should be done is flaffing around with an app on the phone, and making sure someone on the other end happens to have the app installed as well.