Or you can get the OSRAM SMART+ Apple HomeKit Plug - but it's almost twice as expensive...

This Smart+Plug is ZigBee and Alexa compatible -> Directly controllable via Alexa Echo Plus. Otherwise, a Zigbee-capable gateway is necessary (Philips Hue Bridge, for example).
It can also be used directly with Zig-Bee capable smart home hubs such as Homee, Homey or others (since Zig-Bee modules are available).
Only directly via SmartPhone it is not usable.