The app gives detailed information on when the Nest Protect last checked itself, and if there are any issues. From here, you can also silence the alarm if it goes off accidentally while you're cooking a steak, for example. MORE: Smart Home Guide: What to Know Before You BuyAdditionally, you can link the Nest Protect to other smart home systems, such as Google Home and the Mini and Max, TP Link smart plugs and Philips Hue lights. Bottom LineAt $100, the Nest Protect is one of the most expensive, but also one of the most comprehensive, of the smart smoke detectors we've tested. Not only does it pick up several types of fires, as well as carbon monoxide, but it also does the best job at alerting you of the danger. And, it works with a wide range of smart home products. So, for example, you can set your Philips Hue lights to turn on automatically when the Nest Protect goes off. Our budget pick, the Roost Smart Battery $35, is good for those who want to retrofit existing "dumb" smoke detectors to make them smart. It’s inexpensive, sends an alert to your smartphone, and lets you silence the alarm remotely. However, its smart home integration is limited to IFTTT, and its smoke detection capabilities are only as good as the alarm in which you use it. Overall, the Nest Protect is worth the investment.