The $30 Ring Mailbox Sensor -- a simple device that sends alerts to your phone when your mailbox's door opens -- is now available to buy. I got my hands on one, but haven't had the chance to fully ...

In addition to the Ring Always Home Cam, a $250 flying drone/security camera, the Amazon company also quietly introduced a $30 Mailbox Sensor last week via a low-key announcement page. Similar to ...