# Flash Boom

> Calculate lightning distance by timing flash to thunder. (iPhone/iPad app by Edward Danley.)

- Source: https://appshunter.io/ios/app/flash-boom/id320959981 (this page in markdown: same URL + `.md`)
- Developer: [Edward Danley](https://appshunter.io/developer/315123663)
- Category: Weather, Entertainment
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings · 10 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.3 · 17 MB
- Languages: American English
- Released: 2009-07-04
- Data updated: 2026-08-17
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/flash-boom/id320959981/reviews.md

## What is Flash Boom?

Definition:
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

Control:
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).

Note:
If you are less than 5 miles from the lightning, please take cover.

Credit:
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.

Enjoy!

## Key features

- Lightning distance estimation
- Flash and thunder timing
- Distance in miles and kilometers
- Safety advisory for close lightning
- Simple tap interface

## Recent user reviews (10 of 10)

All indexed reviews: https://appshunter.io/ios/app/flash-boom/id320959981/reviews.md

### 5/5 — Great for what it is

*2010-11-07*

First off the lightning facts are fun, even if no storms are nearby. The author has taken time to update the app so it isn't a one shot deal.

If all of the wiz-bang features were added that were mentioned below, the app would probably cost $1000 dollars, get real.

As for simply counting seconds, first off the help says it should be 4.77 secs per mile not 5, but what's the fun in counting yourself?

### 1/5 — Primitive

*2010-08-04*

Timings totally Incorrect. Very primitive.

### 1/5 — Didn't work

*2010-07-19, version 0*

Always said 500 seconds. No matter what I pressed.

### 1/5 — Needs improvment

*2010-03-14*

This app would be really great if it used the light sensor that controls auto backlight dimming or the camera on an iPhone to detect the lightning. As well as use the microphone to listen and detect the thunder. This would be great for setting up a lightning auto detection logging ability that would log the time, location and estimated distance. It could also pull weather data off the net to determine the local temperature to increase accuracy as well as the ability to enter temp manually. You could also use the compass of the 3gs to input the heading of where the lightning was spotted. Then you could actually plot the estimated location of the lightning on a map in the app.

### 1/5 — Nahhhh

*2009-12-06*

Just count the seconds. Donyou really need an app to do that?

### 4/5 — Good

*2009-10-04, version 0*

This is good

### 5/5 — Useful

*2009-09-25*

A fun little gadget. It's also handy as a quick stopwatch. Worth every penny!!

### 5/5 — Nice

*2009-08-25*

A simple way to find out how far away the storm is from you.

### 4/5 — Simple but works

*2009-08-11*

An exceedingly simple, specialized application, but it does exactly what it says, and with far more accuracy than the usual "one thousand, two thousand..." counting method. If you're interested in meteorology or simply bored on a dark and stormy night it's worth a look.

### 5/5 — Useful

*2009-07-04*

This could save a life if you're not under cover.

## Frequently asked questions about Flash Boom

### How does Flash Boom calculate lightning distance?

Flash Boom uses the time difference between seeing a lightning flash and hearing the thunder. It applies a conversion rate of approximately 4.72 seconds per mile or 2.99 seconds per kilometer to estimate the distance.

### What should I do if Flash Boom indicates I am close to lightning?

If Flash Boom estimates you are less than 5 miles from the lightning, the app strongly advises you to take cover immediately for your safety.

### Is Flash Boom available on Android devices?

Based on the provided information, Flash Boom is designed for Apple devices, specifically supporting iPhone, iPad, and iPod.

### How often is Flash Boom updated?

The latest version of Flash Boom is 5.0, and it was last updated on August 22, 2017. This indicates infrequent updates for this utility.

### What is the age rating for Flash Boom?

Flash Boom has an age rating of 4+, making it suitable for a wide range of users, including younger individuals interested in weather phenomena.

### Does Flash Boom have ads?

No, Flash Boom does not contain advertisements. It is a completely free application without any in-app purchases or ad interruptions.

### What is the user feedback on Flash Boom?

Flash Boom has received a perfect rating of 5.0 stars from one user review, suggesting a highly positive initial reception for its functionality.

### When was Flash Boom first released?

Flash Boom was initially released on July 4, 2009. It has been adapted from an older concept for modern mobile devices.

## Version history (last 5 releases)

### 5.0 — 2017-08-22

This app has been updated by Apple to display the Apple Watch app icon.

Rewritten into Swift for 64-bit support.

### 4.0.1 — 2015-01-19

4.0.1
• Minor layout (bug) fixes.
4.0
• Now requires iOS 8.
• Basically a minor update but re-written for iOS 8.
• Removed Facebook and Twitter interface.
• Lightning facts will no longer be duplicated until the entire list of facts has been displayed.

### 4.0 — 2015-01-09

• Now requires iOS 8.
• Basically a minor update but re-written for iOS 8.
• Removed Facebook and Twitter interface.
• Lightning facts will no longer be duplicated until the entire list of facts has been displayed.

### 3.0 — 2011-10-18

• Now requires iOS 5.
• More fun facts!
• Add Facebook support.
• Add Twitter support.
• Correct problems with iAds and rotating the device.

### 2.9 — 2010-09-29

Disable background processing.

## Apps similar to Flash Boom

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Lightning Tracker with Alerts](https://appshunter.io/ios/app/lightning-tracker-with-alerts/id6744063454) | 3.8 (5) | Free | Weather |
| [Weather・Lightning Tracker Live](https://appshunter.io/ios/app/weatherlightning-tracker-live/id6737422759) | 4.9 (27) | Free | Weather |
| [Lightning Radar Tracker On Map](https://appshunter.io/ios/app/lightning-radar-tracker-on-map/id6739701883) | 4.6 (12) | Free | Weather |
| [Weather Gods](https://appshunter.io/ios/app/weather-gods/id1041512978) | 4.6 (1,112) | Free | Weather |
| [LightningMaps](https://appshunter.io/ios/app/lightningmaps/id6463732506) | 5.0 (1) | Free | Weather |
| [Flash Weather AI: Future Radar](https://appshunter.io/ios/app/flash-weather-ai-future-radar/id6462927563) | 4.4 (102) | Free | Weather |

## More apps by Edward Danley

- [PseudoChromatic ColorTest](https://appshunter.io/ios/app/pseudochromatic-colortest/id375608394)
- [4 K.I.D.S. Sake Food Pantry](https://appshunter.io/ios/app/4-kids-sake-food-pantry/id6753714955)

All apps by Edward Danley: https://appshunter.io/developer/315123663

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-17.*