# RockCONNECT vs Doppler Effect Calculator

The clearest difference is price: RockCONNECT at Free against Doppler Effect Calculator's $2.99. RockCONNECT also leads on update cadence (every 2 months vs every 26 months) and iOS requirement (13.0 vs 17.6). On ads, in-app purchases and device support there is nothing between them.

RockCONNECT 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.

RockCONNECT ships an update every 2 months, Doppler Effect Calculator every 26 months. Both last shipped on October 8, 2026.

## The numbers

| Metric | RockCONNECT | Doppler Effect Calculator |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/doppler-effect-calculator/id1410084954/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 26 months |
| Monetization | — | Paid |
| Size | 17 MB | 1 MB |
| Requires iOS | **13.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Ground Control Technologies UK Ltd](https://appshunter.io/developer/1774186724) | [Nitrio](https://appshunter.io/developer/321121189) |

## What reviewers say

### RockCONNECT

[App page](https://appshunter.io/ios/app/rockconnect/id904965550)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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


## Frequently asked questions

### Is RockCONNECT free?

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

### Is Doppler Effect Calculator free?

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

### Do RockCONNECT or Doppler Effect Calculator have ads?

Neither RockCONNECT nor Doppler Effect Calculator shows ads.

### Which is updated more often, RockCONNECT or Doppler Effect Calculator?

RockCONNECT ships an update every 2 months, and Doppler Effect Calculator every 26 months. Most recently, RockCONNECT was updated on October 8, 2026 and Doppler Effect Calculator on October 8, 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.*