# MQTT Spy vs systemsoundtest

The clearest difference is rating: systemsoundtest at 5.0 against MQTT Spy's 4.0. systemsoundtest also leads on in-app purchases (none vs 1) and ads (none vs shown). MQTT Spy's advantage is update cadence (every 4 months vs every 24 months) and device support (4 vs 2). On price and ratings volume there is nothing between them.

MQTT Spy costs $0.99 and systemsoundtest $0.49 up front. MQTT Spy sells 1 one-off in-app purchase. systemsoundtest asks for nothing beyond the download.

systemsoundtest holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

MQTT Spy ships an update every 4 months, systemsoundtest every 24 months. Both last shipped on October 27, 2026.

## The numbers

| Metric | MQTT Spy | systemsoundtest |
| --- | --- | --- |
| Price | $0.99 | **$0.49** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/mqtt-spy/id1564422794/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/systemsoundtest/id6737198486/reviews)** |
| Number of ratings | 1 | 1 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 4 months** | Every 24 months |
| Monetization | **Free with in-app purchases** | Paid |
| Best chart rank | — | **#33** |
| Size | 26 MB | 1 MB |
| Requires iOS | **10.0** | 18.6 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Gopi Gadhiya](https://appshunter.io/developer/1387816354) | [SHUNJI KUSAKA](https://appshunter.io/developer/1738810004) |

## What reviewers say

### MQTT Spy

[App page](https://appshunter.io/ios/app/mqtt-spy/id1564422794)

This application allows for testing the pub/sub MQTT protocol. Connect to an MQTT broker to send and receive messages, control IoT devices, and monitor sensors. It offers features for saving broker lists, custom publishing buttons, and data monitoring in ASCII or HEX.

**Highlights:** Save broker list, Custom publish buttons, Monitor data as ASCII or HEX, Auto-send commands at intervals, Keep screen on/off option, Send log files

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $2.99 | one-time |


### systemsoundtest

[App page](https://appshunter.io/ios/app/systemsoundtest/id6737198486)

**Currently charting:** #33 Top Paid · Developer Tools (US App Store)

Explore over 100 official iOS system sounds with a clean, modern interface. Tap buttons to instantly play notification tones and alerts, with dynamic visual feedback.

**Highlights:** Over 100 official iOS system sounds, Instant sound playback, Clean, user-friendly interface, Dynamic button color changes, Explore notification tones and alerts

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

**In-app purchases:** none


## Frequently asked questions

### Is MQTT Spy free?

MQTT Spy costs $0.99, and also offers in-app purchases.

### Is systemsoundtest free?

systemsoundtest costs $0.49, with no in-app purchases.

### Which has better reviews, MQTT Spy or systemsoundtest?

systemsoundtest is rated higher. MQTT Spy averages 4.0 out of 5 from 1 ratings, while systemsoundtest averages 5.0 from 1 ratings.

### Do MQTT Spy or systemsoundtest have ads?

MQTT Spy shows ads; systemsoundtest does not.

### Which is updated more often, MQTT Spy or systemsoundtest?

MQTT Spy ships an update every 4 months, and systemsoundtest every 24 months. Most recently, MQTT Spy was updated on October 27, 2026 and systemsoundtest on October 27, 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.*