This is a really cool device and project. I can imagine many other uses for the AirDog beyond sport practice... but the I really like it because it makes me recall some videogame heroes ;-)
But I'm a bit concerned about the legal issues around using drones. In Spain, the Government plans to establish a new "drone driving license": you must be a certified "drone pilot" in order to fly your own device.
Just an example: this week a guy was fined for using a drone in order to record the Running of the Bulls at Pamplona's Sanfermines.