# Sonar Ruler vs Secret

The clearest difference is update cadence: Secret at every 10 months against Sonar Ruler's every 94 months. Secret also leads on rating (3.0 vs 2.7) and review sentiment (55% vs 43%). Sonar Ruler's advantage is ratings volume (3 vs 1) and iOS requirement (8.1 vs 26.0). On price, ads, in-app purchases and monetization model there is nothing between them.

Sonar Ruler costs $0.99 and Secret $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Secret holds the better App Store score, 3.0 against 2.7. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews point the same way: 43% of Sonar Ruler's written reviews are positive against 55% of Secret's.

Sonar Ruler ships an update every 94 months, Secret every 10 months. The most recent releases landed on October 18, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Sonar Ruler | Secret |
| --- | --- | --- |
| Price | $0.99 | $0.99 |
| Rating | [2.7 (3 ratings)](https://appshunter.io/ios/app/sonar-ruler/id324621243/reviews) | **[3.0 (1 ratings)](https://appshunter.io/ios/app/secret/id405805873/reviews)** |
| Number of ratings | **3** | 1 |
| Positive reviews | 43.5% of reviews | **54.5% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 94 months | **Every 10 months** |
| Monetization | Paid | Paid |
| Size | 13 MB | 11 MB |
| Requires iOS | **8.1** | 26.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Laan Labs](https://appshunter.io/developer/310916919) | [curmi.com](https://appshunter.io/developer/354900328) |

## 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)


### Secret

[App page](https://appshunter.io/ios/app/secret/id405805873)

Securely send and receive encrypted messages that only the intended recipient can read. Protect your private conversations with end-to-end encryption and a password. Messages are not stored on your device after decryption.

**Highlights:** End-to-end message encryption, Password protection for decryption, Shake to clear messages, Messages not stored on device, Supports any language and emoji, Multiple language localizations

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Sonar Ruler free?

Sonar Ruler costs $0.99, with no in-app purchases.

### Is Secret free?

Secret costs $0.99, with no in-app purchases.

### Which has better reviews, Sonar Ruler or Secret?

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

### Do Sonar Ruler or Secret have ads?

Neither Sonar Ruler nor Secret shows ads.

### Which is updated more often, Sonar Ruler or Secret?

Sonar Ruler ships an update every 94 months, and Secret every 10 months. Most recently, Sonar Ruler was updated on October 18, 2026 and Secret on October 13, 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.*