Roost's smart smoke alarm connects to Wi-Fi, comes with a companion app, and lets you know when it's low on battery. The alarm also alerts you and your loved ones when it detects smoke, just to make sure everyone is good and worried. It relies on Roost's smart battery, which connects to Wi-Fi. The alarm itself isn't connected until the battery is in place. Roost also sells the battery by itself, which home owners can use to make their not-smart smoke detector a connected one.
The $60 version of Roost's alarm monitors only smoke, whereas the $80 version detects smoke, carbon monoxide, fire, and natural gas. This is cheaper than Nest's all-in-one detector, which retails for $99.