The purpose of Flash Boom is simple. It will give you an estimate of how far away lightning is. The rule of thumb says to allow about 5 seconds for each mile (3 seconds for each kilometer). In reality it is more like 4.72 seconds per mile and 2.99 seconds per kilometer. For more details, please visit http://www.wikihow.com/Calculate-the-Distance-from-Lightning
Tap the FLASH button when you see the lightning. The button will change to BOOM. Tap the BOOM button when you hear the thunder. Thunder will usually not travel more than 15 miles (24 kilometers).
If you are less than 5 miles from the lightning, please take cover.
The original Flash Boom program I knew of was writen by Kim Moelgaard for the Palm OS. I adapted the concept (without access to the code) to the iPhone.
Rewritten into Swift for 64-bit support.
가족 공유를 설정하면 최대 6명의 가족 구성원이 이 앱을 사용할 수 있습니다.