if you're looking to communicate through the system, it's not practical. it implies that you can, but you have to hook up an external speaker and a microphone to do so. even then, its only where you put them and not through each camera.
picture quality through the app is not as good as you would think. its good to tell what someone is wearing, but you can't read their shirt, and forget about getting licensplates.
It's not worth the hastle to return it, but if I knew, I would have spent the money for a better system.