Flash Boom is a lightning distance calculator.
There is support for both Km and Miles in the distance display.
Tap the lightning symbol when you see the flash. Tap the boom symbol when you hear the boom.
The distance will be displayed numerically and shown by a little cloud icon relative to the man. The distance from the man to the cloud may be set in preferences.
The distanceunit may be altered between Km and Miles. This is also done in preferences.