This is a great deal on SimpliSafe Video Doorbell on sale for $60 off regular price at Sam's Club. This camera can be added to the gen 2 and 3 systems. Existing doorbell wiring required and is easy to setup.
From Product Page:
Sends text alerts when movement is detected
Uses multiple sensors to detect people and ignore distractions like cars and pets
Designed to replace doorbells on a variety of homes
Choose from an array of colorful faceplates, which included in every package