# Sonar Ruler vs Currency Converter

The clearest difference is price: Sonar Ruler at Free against Currency Converter's $1.99. Sonar Ruler also leads on ratings volume (3 vs 1). Currency Converter's advantage is update cadence (every 2 months vs every 105 months) and rating (3.0 vs 2.7). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Sonar Ruler is free to download; Currency Converter costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Currency Converter holds the better App Store score, 3.0 against 2.7. Both are backed by a comparable volume of ratings — 3 and 1 respectively.

Sonar Ruler ships an update every 105 months, Currency Converter every 2 months. The most recent releases landed on November 12, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | Sonar Ruler | Currency Converter |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | [2.7 (3 ratings)](https://appshunter.io/ios/app/sonar-ruler/id324621243/reviews) | **[3.0 (1 ratings)](https://appshunter.io/ios/app/currency-converter-forex-tool/id6804119586/reviews)** |
| Number of ratings | **3** | 1 |
| Positive reviews | 43.5% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 105 months | **Every 2 months** |
| Monetization | Paid | — |
| Size | 5 MB | 3 MB |
| Requires iOS | 18.0 | **17.6** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Laan Labs](https://appshunter.io/developer/310916919) | [乐祥 胡](https://appshunter.io/developer/1572365721) |

## What reviewers say

### Sonar Ruler

[App page](https://appshunter.io/ios/app/sonar-ruler/id324621243)

This experimental app uses your iPhone's speaker to send out sonic pulses and measures the echo to estimate distances up to 60 feet. It's a fun and innovative way to explore sonar principles, perfect for educational purposes or impressing friends with unique iPhone capabilities.

**Highlights:** Sonic distance measurement, Up to 60 feet range, Selectable units (feet, inches, meters), Custom saved settings, Educational sonar demonstration

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💡 Innovative sonar technology using iPhone hardware
- 🎯 Accurate measurements when used correctly (±0.5-1 inch)
- 📚 Educational value for learning sound principles
- 🎮 Fun novelty app for impressing friends
- ⚙️ Customizable settings for different environments

**What reviewers complain about**

- 🐛 Crashes immediately on many iPhone models
- ❌ Doesn't work on older iPhone generations (iPhone 4, 4S, 5)
- 🔊 Highly sensitive to background noise and interference
- 😕 Steep learning curve and unintuitive interface
- ⚠️ Inconsistent and unreliable measurements

**Reported bugs**

- App crashes within 3 seconds of opening on iPhone 6 and older models
- Won't open on iOS 8.4 and later versions
- No chirping sound emitted on some devices
- Feedback loop and screaming noise on certain hardware
- Phone locks up requiring hard restart

**Requested features**

- Room mapping by rotating phone in circle
- Vertical distance measurement capability
- Better ambient noise filtering
- Clearer, more intuitive user interface
- Optimized default settings (frequency, filter, chirp)


### Currency Converter

[App page](https://appshunter.io/ios/app/currency-converter-forex-tool/id6804119586)

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

**In-app purchases:** none


## Frequently asked questions

### Is Sonar Ruler free?

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

### Is Currency Converter free?

Currency Converter costs $1.99, with no in-app purchases.

### Which has better reviews, Sonar Ruler or Currency Converter?

Currency Converter is rated higher. Sonar Ruler averages 2.7 out of 5 from 3 ratings, while Currency Converter averages 3.0 from 1 ratings.

### Do Sonar Ruler or Currency Converter have ads?

Neither Sonar Ruler nor Currency Converter shows ads.

### Which is updated more often, Sonar Ruler or Currency Converter?

Sonar Ruler ships an update every 105 months, and Currency Converter every 2 months. Most recently, Sonar Ruler was updated on November 12, 2026 and Currency Converter on November 10, 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.*