The Ring WIFI Doorbell is now available in multiple colours to suit your taste. Ring uses WIFI to connect to your home Internet connection and sends a notification to your iOs or Android device(s) when someone comes to the door. You can choose to get an alert only when they press the doorbell button, or you can get notified automatically when someone approaches. Choose to ignore or answer to watch live video and have a two way voice chat with the guest (or unwanted visitor).
Check out Ring here: https://www.aartech.ca/ring-wifi-doorbell.html
The Ring doorbell can be powered by battery with up to a year between charges, or can be connected to an existing doorbell in which case it has full time power. When hardwired it can ring your existing mechanical doorbell as well as alerting your smart devices. Plus, add a plug-in extension chime where needed.
The Ring doorbell adds convenience and enhances security with a hint of deterrence.