The most obvious and important application of video door phone system is constant monitoring on your doorway and visitor's/passer - by's in your foyer. If any misdeed is observed, authorities can be quickly notified about the same in real time.
It is pretty easy to communication with visitor's at your doorstep without granting them entry into your house. Often times deliverymen and other require access to your person and your initials. They can be verified by having a video door phone system with a two way communication method and accordingly grant or deny them access into your house.
It is always a good idea to maintain record or log of people visiting your house. And what works better than a video door phone system? It eliminates the need of having a log book or a doorkeeper to maintain a log records of every individuals. It also provides the added benefits of precise time stamps and eliminates of human errors.
A smart door phone systems provides total control to you from wherever you are, thus granting easy access to your house is in your hands. Even if you are out of your house and your maid requires access to your house. This can be done by a simple tap on your smartphone.