# Flash Boom vs Lightning Alarm

The clearest difference is rating: Flash Boom at 5.0 against Lightning Alarm's 4.5. Flash Boom also leads on in-app purchases (none vs 4) and ads (none vs shown). Lightning Alarm's advantage is ratings volume (889 vs 1) and review sentiment (80% vs 60%). On price, update cadence and device support there is nothing between them.

Both are free to download. Lightning Alarm sells 4 in-app purchases, starting at $2.99 per year. Flash Boom asks for nothing beyond the download.

Flash Boom holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Lightning Alarm has 889 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 60% of Flash Boom's written reviews are positive against 80% of Lightning Alarm's, so the app with the better star average is not the one people write more warmly about.

Flash Boom ships an update every 6 weeks, Lightning Alarm every 2 months. The most recent releases landed on September 27, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | Flash Boom | Lightning Alarm |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/flash-boom/id320959981/reviews)** | [4.5 (889 ratings)](https://appshunter.io/ios/app/lightning-alarm/id1015876499/reviews) |
| Number of ratings | 1 | **889** |
| Positive reviews | 60.0% of reviews | **80.5% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 6 weeks** | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 17 MB | 79 MB |
| Requires iOS | **10.3** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Edward Danley](https://appshunter.io/developer/315123663) | [Infoplaza BV](https://appshunter.io/developer/419311197) |

## What reviewers say

### Flash Boom

[App page](https://appshunter.io/ios/app/flash-boom/id320959981)

This app estimates the distance to lightning strikes by timing the interval between seeing the flash and hearing the thunder. It provides a simple, quick way to gauge your proximity to a storm and advises taking cover if you are within 5 miles.

**Highlights:** Lightning distance estimation, Flash and thunder timing, Distance in miles and kilometers, Safety advisory for close lightning, Simple tap interface

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Lightning Alarm

[App page](https://appshunter.io/ios/app/lightning-alarm/id1015876499)

Receive timely notifications about approaching thunderstorms and lightning strikes in your vicinity. This app provides accurate lightning detection and displays real-time information on a map, ensuring safety during outdoor activities.

**Highlights:** Real-time lightning detection, Approaching storm notifications, Lightning distance display, Map view of lightning strikes, Textual storm information, Push message alerts

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lightning Alarm Premium | $2.99 | per year |
| 1 month ad free | $0.99 | one-time |
| 3 months ad free | $1.99 | one-time |
| 1 year ad free | $2.99 | one-time |

**What reviewers like**

- ⭐️ Excellent app
- 👍 Works great
- 🚀 Accurate and precise
- 🔔 Helpful notifications
- 🌩️ Tracks lightning effectively

**What reviewers complain about**

- 🐛 App crashes or freezes
- ⚠️ Inaccurate or unreliable
- 🔍 Difficult to set location
- 🔢 Metric units not preferred

**Reported bugs**

- Notifications not working
- Map tiles not loading properly
- App crashing on launch

**Requested features**

- Option to switch between miles and kilometers
- Add multiple locations to track
- Improve map visuals and details
- Customizable alert radius


## Frequently asked questions

### Is Flash Boom free?

Flash Boom is free to download, with no in-app purchases.

### Is Lightning Alarm free?

Lightning Alarm is free to download, with in-app purchases available.

### Which has better reviews, Flash Boom or Lightning Alarm?

Flash Boom is rated higher. Flash Boom averages 5.0 out of 5 from 1 ratings, while Lightning Alarm averages 4.5 from 889 ratings.

### Do Flash Boom or Lightning Alarm have ads?

Lightning Alarm shows ads; Flash Boom does not.

### Which is updated more often, Flash Boom or Lightning Alarm?

Flash Boom ships an update every 6 weeks, and Lightning Alarm every 2 months. Most recently, Flash Boom was updated on September 27, 2026 and Lightning Alarm on October 16, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*