A crack of lightning can illuminate the sky for an instant, but it often has a deadly impact here on earth. In Odisha, for example, lightning claims about 400 lives every year — more than that by any other natural calamity. To tackle the effect of these bolts from the blue, the government of Odisha is all set to introduce a mobile app called Satark (caution) that will not only provide early warning of lightning to users, but also send out alerts to anyone whose presence is detected through their mobile signal in an area which is at risk from