First things first: The Eve Extend doesn’t actually do anything in the traditional sense. It can’t control your lights, alert you to motion, tell you if your windows or doors are open, or report the weather. What it does is serve as a bridge between Eve’s Bluetooth-enabled, HomeKit-compatible smart devices and your Wi-Fi network, freeing you from the range limitations inherent to Bluetooth.
If you haven’t already invested in the HomeKit-oriented Eve smart home ecosystem (lighting controls; air-quality monitors; door, window, and motion sensors; and the like), Eve Extend won’t interest you in the least. But if you’ve used a Bluetooth-based smart home product from any vendor, you’ve probably experienced the problem that Eve Extend is designed to solve: Controlling a Bluetooth device with your smartphone is piece of cake—provided you’re relatively close by.