Zooz Z-Wave Power Switch
The Zooz ZEN15 Power Switch is by far my favorite connected power switch. It is robust, can handle a lot of power, and has a considerate cord design. We use these all around the house from sending us notifications when the washer/dryer finish to switching grow lights, these switches have never given us any trouble.
Include/Exclude
Zooz provides solid instructions for inclusion and exclusion but here's a quick summary.
Indicators
Flashing blue: include mode
Flashing green: secure include mode
Flashing orange: exclude mode
Single flash Blue or Pink: success
Solid orange: successful exclude
Inclusion
If it doesn't flash blue when plugged in, hit the button 3 times fast for regular inclusion - or hold for 3 seconds for secure inclusion.
Exclusion
Press the button 3 times fast.