You can already buy connected ranges that offer remote control and prevent kitchen disasters. But what about your existing range -- are you really going to replace it just for some extra convenience and peace of mind? You might not have to. Inirv is crowdfunding the React, a smart stove knob system that upgrades most any electric or gas stove. You can control individual burners through your phone, of course, but the real star of the show is a sensor that sits on your ceiling. If it detects gas, smoke or prolonged inactivity, it automatically shuts off active burners. You shouldn't have to worry about sparking a house fire just because you forgot to switch the stove off before you left for the movies.