# Doppler Effect Calculator vs FlashAlert Flashlight & Strobe

The clearest difference is price: FlashAlert Flashlight & Strobe at Free against Doppler Effect Calculator's $2.99. FlashAlert Flashlight & Strobe also leads on iOS requirement (15.0 vs 17.6). On rating, ratings volume, update cadence and ads there is nothing between them.

FlashAlert Flashlight & Strobe is free to download; Doppler Effect Calculator costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Doppler Effect Calculator against 5.0 for FlashAlert Flashlight & Strobe. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

Doppler Effect Calculator ships an update every 26 months, FlashAlert Flashlight & Strobe every 17 months. The most recent releases landed on November 2, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Doppler Effect Calculator | FlashAlert Flashlight & Strobe |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/doppler-effect-calculator/id1410084954/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/flashalert-flashlight-and-strobe/id6743496732/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 26 months | **Every 17 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 26 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Andreas Conradi Nitschke](https://appshunter.io/developer/1641513251) |

## What reviewers say

### Doppler Effect Calculator

[App page](https://appshunter.io/ios/app/doppler-effect-calculator/id1410084954)

This physics and math calculator helps determine the frequency of sound waves when the source or observer is in motion. It provides instant calculations with copyable results and includes reference formulas. The app supports various units and high precision, working seamlessly on iOS devices.

**Highlights:** Instant calculations, Copyable results, Reference formulas included, Supports 16 decimal places, Multiple unit support, Ad-free and private

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

**In-app purchases:** none


### FlashAlert Flashlight & Strobe

[App page](https://appshunter.io/ios/app/flashalert-flashlight-and-strobe/id6743496732)

This utility app provides a quick and dependable flashlight function with additional emergency strobe and SOS modes. It offers a convenient shake-to-toggle feature for easy activation, making it ideal for nighttime use and safety situations.

**Highlights:** Fast flashlight, Emergency strobe mode, SOS mode, Shake to toggle, Night use, Safety feature

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

**In-app purchases:** none


## Frequently asked questions

### Is Doppler Effect Calculator free?

Doppler Effect Calculator costs $2.99, with no in-app purchases.

### Is FlashAlert Flashlight & Strobe free?

FlashAlert Flashlight & Strobe is free to download, with no in-app purchases.

### Which has better reviews, Doppler Effect Calculator or FlashAlert Flashlight & Strobe?

Doppler Effect Calculator and FlashAlert Flashlight & Strobe are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do Doppler Effect Calculator or FlashAlert Flashlight & Strobe have ads?

Neither Doppler Effect Calculator nor FlashAlert Flashlight & Strobe shows ads.

### Which is updated more often, Doppler Effect Calculator or FlashAlert Flashlight & Strobe?

Doppler Effect Calculator ships an update every 26 months, and FlashAlert Flashlight & Strobe every 17 months. Most recently, Doppler Effect Calculator was updated on November 2, 2026 and FlashAlert Flashlight & Strobe on October 30, 2026.

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