# Sonar Ruler vs Silent Drop

The clearest difference is iOS requirement: Silent Drop at 16.0 against Sonar Ruler's 18.0. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | Sonar Ruler | Silent Drop |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.7 (3 ratings)](https://appshunter.io/ios/app/sonar-ruler/id324621243/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 43.5% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 105 months | — |
| Monetization | Paid | — |
| Size | 5 MB | 1 MB |
| Requires iOS | 18.0 | **16.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Laan Labs](https://appshunter.io/developer/310916919) | [琳 陆](https://appshunter.io/developer/1836824413) |

## 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)


### Silent Drop

[App page](https://appshunter.io/ios/app/silent-drop-secure-bridge/id6754679221)

**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 Silent Drop free?

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

### Do Sonar Ruler or Silent Drop have ads?

Neither Sonar Ruler nor Silent Drop shows ads.

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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.*