At $32, the Koogeek Smart Plug P1 aims to be the smart plug for every platform, but I wouldn't rush out and buy one. The plug works well with HomeKit, but with an oversized design and an Alexa skill that's unreliable at best, it isn't as good as it could be.
Let's start with Koogeek's design. I like the simple approach, but the problem is the device's size. The Smart Plug P1 measures 2.6 inches on all sides. When plugged into the top receptacle of a standard wall outlet, Koogeek's plug covers the receptacle below it. In order to use both receptacles of a wall outlet, you'll need to place this smart plug on the bottom. If you'd like two smart plugs in one wall outlet, Koogeek isn't an option. Meanwjile, HomeKit-compatible competitors such as the, the and the all take care not to obstruct adjacent outlets.
Setting up the Koogeek Smart Plug P1 begins like most HomeKit devices, by downloading the Koogeek app and scanning the Apple Home code either in the plug's printed user manual or on the plug itself. From there, you can name the device and assign it to a room in your home. The plug automatically appears in your Apple Home app.
Pairing the Smart Plug P1 with Amazon Alexa and Google Assistant isn't nearly as intuitive. On an iOS device, a long press of the smart plug icon on the Koogeek menu reveals plug details. From there, a submenu called third-party connections displays the option to configure Alexa and Google Assistant integration. Tap the name of your desired assistant, and the app automatically configures the plug -- or at least it says it does. After a "configuration successful" message, I found I still needed to open the Google Home ($89 at Crutchfield) app, add a device and log into my Koogeek account to pair the plug. Once paired, the Smart Plug P1 did work well with Google Assistant voice commands.