They say that if you count the number of seconds between blasts of thunder and the lightning flashes, you can tell whether a storm is approaching or fading away.
Never mind all of that. Now you can do it scientifically.
Flash Boom is a lightning distance calculator. With Flash Boom, you can estimate the distance to the electric barrages that light up the sky.
Select kilometers or miles in the distance display. Set the distance of the cloud relative to your position with the special icon, and you're all set. | 
