For instance, three quick knocks on the wall could switch on the lights, while two could activate the thermostat. A couple of slow taps on the bedside table could activate the coffeemaker while you're still in bed, while a knock on your door could send you a text message that someone's visiting. The device uses non-acoustic sensor technology, so it doesn't get confused with random sounds. Plus, its creator says it can differentiate between random vibrations and deliberate knocks.

Knocki works with Nest, Philips Hue, Wemo, Samsung Smartthings and apps like Spotify and Gmail. But if you haven't transformed your house into a high-tech home yet, it can also control phones and other wifi-connected appliances like speakers and alarm clocks. The campaign is still ongoing, and you can get one sensor for $69. If all goes according to the company's plan (don't forget that they sometimes don't) Kickstarter backers should get their rewards by December.