3. Nest Hello features HD Talk and Listen so you can speak to whoever's outside. For those times when you're otherwise engaged, the Nest Hello app has a quick response feature, which plays a voice message. Nest touts that capability as a quick way to handle package deliveries without having to come to the door. A more clever addition to the app is a nap time feature that silences the door chime while still sending notifications to the phone. It sounds like a handy way not to be interrupted by a doorbell.