99View at Newegg Business$127. 65View at Amazon?Voice alarm tells you where danger is and how to proceedMobile app connects smoke detectors, thermostats and security camerasConnects to a variety of smart home networksHas a relatively short warranty period of two yearsIsn’t compatible with Amazon AlexaIsn’t compatible with Apple HomeKitIn addition to the standard tone alarm, the Next Protect features a voice alarm that calmly tells you about the danger, where it is and how to proceed. If you happen to be away when an emergency occurs, this smoke alarm’s mobile app notifies you immediately. This allows you to contact emergency services and potentially avoid the worst of the damage. The app also lets you monitor what’s happening in your home and test alarms remotely, and it teaches you how to best use your smoke detector. This smoke alarm is only one piece of Nest’s larger home automation system. Not only can you network multiple Nest Protect units together, but you can also connect other Nest devices such as thermostats and security cameras. Additionally, the Nest Protect is compatible with other smart home networks including Nexia, Vera, Wink and Google Home; it doesn't work with Amazon Alexa or Apple HomeKit. Unfortunately, the two year warranty is shorter than those from First Alert and Kidde. Read the full reviewBest ValueKidde KN COSM B RF$49. 72 View at AmazonCheck Walmart?Detects both smoke and carbon monoxideDoesn’t require a hardwired connectionCan connect to multiple alarms via Wi FiPerformed poorly in our detection testsRequires extra equipment for the mobile appOnly compatible with Wink smart home platformThis alarm is two devices in one: a smoke detector and a carbon monoxide detector.