USB Wifi Switch On/Off

You know all the sonoff wifi switches (you wire it inline and then toggle it on/off via app/wifi)
I am looking for something that can connect to USB micro and do the same, i.e. allow we to toggle the power on/off via wifi (I will used it to toggle a tablet charging on/off)
Not sure what exactly is even called, can someone point me in the right direction if you have come across this.

If you’re willing to roll up the sleeves and DIY, you could look at this:

It looks like Sonoff is releasing a WiFi USB smart adaptor on the Feb 15th.