Amazon’s Ring security camera business has unveiled the Ring Always Home Cam, which is a camera that flies around your home to monitor the parts of your home you choose.
According to Ring, the user sets up personalised paths and then, when they want to monitor one of these paths, the user can initiate this instruction remotely.
This is quite unique, and if you could do it on command, also a way to check if you left a window open or a door etc. Not sure how it navigates up or down stairs though 
See Watch – Ring launches security camera drone that flies around your house
Amazon’s Ring security camera business has unveiled the Ring Always Home Cam, which is a camera that flies around your home to monitor the parts of your home you choose.