You don`t you worry about who is in front of your house, if you are not at home. RING is a SMART-RING that alerts you if someone is arriving to your home that works with a movement detector that sends direct information to your phone, first with an alarm and then with a video where you can see what is going on at your home entrance.
The user can recieve all this information through your cell phone. Also allows you to talk with the person who is at the other side (your home).
You can have a 180 degree vision with night sight also. It communicates via WiFi and has a rechargable battery that last a year.
RING works with a dedicated app on iPhones and Androids.