# smartMFD by Guardian Avionics vs Decibel Meter Plus Pro

The clearest difference is price: smartMFD by Guardian Avionics at Free against Decibel Meter Plus Pro's $6.99. smartMFD by Guardian Avionics also leads on in-app purchases (none vs 1) and iOS requirement (13.0 vs 15.0). Decibel Meter Plus Pro's advantage is ratings volume (81 vs 3). On rating, update cadence, ads and device support there is nothing between them.

smartMFD by Guardian Avionics is free to download; Decibel Meter Plus Pro costs $6.99 up front. Decibel Meter Plus Pro sells 1 one-off in-app purchase. smartMFD by Guardian Avionics asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 3.7 for smartMFD by Guardian Avionics against 3.8 for Decibel Meter Plus Pro. That said, the two scores are not equally well evidenced: Decibel Meter Plus Pro has 81 ratings behind it against 3, so its average is the more settled of the two.

smartMFD by Guardian Avionics ships an update every 3 months, Decibel Meter Plus Pro every 2 months. The most recent releases landed on November 6, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | smartMFD by Guardian Avionics | Decibel Meter Plus Pro |
| --- | --- | --- |
| Price | **Free** | $6.99 |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/smartmfd-by-guardian-avionics/id599071174/reviews) | **[3.8 (81 ratings)](https://appshunter.io/ios/app/decibel-meter-plus-pro/id645214476/reviews)** |
| Number of ratings | 3 | **81** |
| Positive reviews | — | 52.8% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 months** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 121 MB | 12 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Co guardian llc](https://appshunter.io/developer/599071177) | [华芳 张](https://appshunter.io/developer/586041482) |

## What reviewers say

### smartMFD by Guardian Avionics

[App page](https://appshunter.io/ios/app/smartmfd-by-guardian-avionics/id599071174)

This app transforms your mobile device into a multifunction display for aircraft, showing flight data, engine performance, and navigation charts. It records flight data for later analysis and provides alerts for carbon monoxide levels and pulse oximetry when connected to compatible hardware.

**Highlights:** Multifunction display (MFD), Flight data recording and analysis, Engine performance monitoring, VFR/IFR charts and approach plates, CO level alerts, Pulse oximeter readings

**In-app purchases:** none


### Decibel Meter Plus Pro

[App page](https://appshunter.io/ios/app/decibel-meter-plus-pro/id645214476)

Measure the sound levels around you with this utility app. It displays average, peak, and max values, offers decibel exposure time guidelines, and provides information on noise-induced hearing loss. The app also allows data recording and export for analysis.

**Highlights:** Measure sound levels, Display average, peak, and max values, Decibel exposure time guidelines, Information on noise-induced hearing loss, Record and export data, Calibrate measurements, Universal app support

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited Reports | $0.99 | one-time |


## Frequently asked questions

### Is smartMFD by Guardian Avionics free?

smartMFD by Guardian Avionics is free to download, with no in-app purchases.

### Is Decibel Meter Plus Pro free?

Decibel Meter Plus Pro costs $6.99, and also offers in-app purchases.

### Which has better reviews, smartMFD by Guardian Avionics or Decibel Meter Plus Pro?

Decibel Meter Plus Pro is rated higher. smartMFD by Guardian Avionics averages 3.7 out of 5 from 3 ratings, while Decibel Meter Plus Pro averages 3.8 from 81 ratings.

### Do smartMFD by Guardian Avionics or Decibel Meter Plus Pro have ads?

Neither smartMFD by Guardian Avionics nor Decibel Meter Plus Pro shows ads.

### Which is updated more often, smartMFD by Guardian Avionics or Decibel Meter Plus Pro?

smartMFD by Guardian Avionics ships an update every 3 months, and Decibel Meter Plus Pro every 2 months. Most recently, smartMFD by Guardian Avionics was updated on November 6, 2026 and Decibel Meter Plus Pro 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.*