The $100 Kidde RemoteLync Monitor promises to do one thing: it'll listen for the alarms of smoke and carbon monoxide detectors and will send a push notification to your phone should they sound. You'll use the iOS or Android app to connect it to your Wi-Fi network, then it'll spend the rest of its 10 year life trying hard to be a good listener.
It succeeds if the sounding smoke detector is close enough, but don't expect it to cover your whole home if you have multiple floors. You can purchase the US-only Kidde RemoteLync Monitor now for $100 from the company's site, Amazon and Home Depot. Aside from an overlong setup process, it works well enough if you find it at a discount, but the Kidde Monitor doesn't do enough or hear far enough to be worth the $100 price.
I plugged the Kidde RemoteLync Monitor into a hallway outlet of the CNET Smart Home. When I set off a smoke detector from that hallway or an adjacent room, I'd reliably get a push notification within 20 to 30 seconds. That's a fine turnaround time, albeit not exceptional.
Still, it was responsive. Even when I shut the door of the adjacent bedroom, the push notification came through with the same moderate punctuality. In a room at the other end of the hallway, the notification sometimes took 40 seconds to arrive, but were still reliable. Once I moved upstairs, though, I had to have a clear line of sight for the RemoteLync Monitor to work. After I shut a single door or rounded a corner, the Monitor became sporadic at best and deaf most of the time.