# fx12 vs Hardness Conversion Master

The clearest difference is in-app purchases: fx12 at none against Hardness Conversion Master's 1. fx12 also leads on ads (none vs shown). Hardness Conversion Master's advantage is update cadence (every 3 days vs fortnightly). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Hardness Conversion Master sells 1 one-off in-app purchase. fx12 asks for nothing beyond the download.

fx12 ships an update fortnightly, Hardness Conversion Master every 3 days. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | fx12 | Hardness Conversion Master |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/fx12-free-flight-models/id1518495325/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Fortnightly | **Every 3 days** |
| Monetization | Free | — |
| Size | 53 MB | 259 MB |
| Requires iOS | 18.0 | **17.6** |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Favionics](https://appshunter.io/developer/495997736) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### fx12

[App page](https://appshunter.io/ios/app/fx12-free-flight-models/id1518495325)

This app provides a real-time interface for viewing and changing parameters of compatible devices, including altimeter and GPS data. It offers enhanced charting, usability improvements, and new flight analysis tools. An optional Apple Watch app allows for remote telemetry viewing and model control.

**Highlights:** Real-time altimeter and GPS data viewing, Parameter control for compatible devices, Improved charting with intuitive UI, New terrain view on maps, Dedicated timer view for flight parameters, 3D flight visualization (Beta), Advanced flight analysis tools (Beta)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Hardness Conversion Master

[App page](https://appshunter.io/ios/app/hardness-conversion-master/id6760411989)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |


## Frequently asked questions

### Is fx12 free?

fx12 is free to download, with no in-app purchases.

### Is Hardness Conversion Master free?

Hardness Conversion Master is free to download, with in-app purchases available.

### Do fx12 or Hardness Conversion Master have ads?

Hardness Conversion Master shows ads; fx12 does not.

### Which is updated more often, fx12 or Hardness Conversion Master?

fx12 ships an update fortnightly, and Hardness Conversion Master every 3 days. Most recently, fx12 was updated on November 3, 2026 and Hardness Conversion Master on October 31, 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.*