Your old, unused gadgets could enjoy a second life protecting your home, said Sean Captain at Fast Company. Perch, a New York City–based startup, turns any internet-connected device with a camera, including tablets, smartphones, and laptops, into a live-streaming security system. Homeowners can tune into lag-free video feeds via Perch's app, as well as access archived video.

The software's image analysis can also tell "who or what is moving around the house," so it won't send an alert if, say, the cat walks in front of the camera. Perch's software will soon work with smart TVs and home automation systems that can be triggered by certain actions. "If you want the stereo to blare loud music when your dog jumps on the sofa, to scare off the dog, you can do that," says CEO Andrew Cohen. For now, the basic service is free, with premium packages to be added later.