I have one to
A friend has one and she gets an alert on her phone when someone approaches the door. So its a good idea
I have the first version, it's actually pretty rubbish, as others have said by the time it shows up on your phone the person at the door has left. It's quite an amazing bit of marketing to persuade so many people to buy such a rubbish bit of kit for such an extortionate price, and then pay extra for the chime and the transformer.
Ring my bell, ding-dong-ding, XD
Bailiffs, doorstep sellers, TVL inspectors, JW, any other unwanted visitors.