# RST 599xp vs Modal Math

The clearest difference is price: Modal Math at Free against RST 599xp's $2.99. Modal Math also leads on device support (3 vs 1). RST 599xp's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 15.1). On rating, ratings volume, update cadence and ads there is nothing between them.

Modal Math is free to download; RST 599xp costs $2.99 up front. Modal Math sells 2 in-app purchases, starting at $24.99 per month. RST 599xp asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for RST 599xp against 5.0 for Modal Math. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

RST 599xp ships an update every 2 months, Modal Math every 5 weeks. The most recent releases landed on October 13, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | RST 599xp | Modal Math |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/rst-599xp/id1524193178/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/modal-math/id6469200381/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 40 MB | 75 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [koji kamogawa](https://appshunter.io/developer/1488210713) | [Asledu LLC](https://appshunter.io/developer/1711677950) |

## What reviewers say

### RST 599xp

[App page](https://appshunter.io/ios/app/rst-599xp/id1524193178)

This app simulates amateur radio CW QSOs with realistic call signs, signal levels, and speeds. It supports various QSO styles, including contest and rubber stamp, with features like pile-up reproduction and RIT control.

**Highlights:** CW QSO simulation, Realistic call signs and signal levels, Pile-up reproduction (up to 3 stations), RIT and CW filter functions, Spectrum scope display, Contest and rubber stamp QSO styles

**Features:** macOS Compatibility

**In-app purchases:** none


### Modal Math

[App page](https://appshunter.io/ios/app/modal-math/id6469200381)

This app provides accessible math practice designed by teachers for students with special language needs. It focuses on fostering conceptual understanding and reinforcing mathematical language for diverse learners.

**Highlights:** Designed by teachers, Accessible for special language needs, Fosters conceptual understanding, Reinforces mathematical language, Supports diverse learning needs

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Classroom Membership | $24.99 | per month |
| DHH Teacher Resources | $6.99 | one-time |


## Frequently asked questions

### Is RST 599xp free?

RST 599xp costs $2.99, with no in-app purchases.

### Is Modal Math free?

Modal Math is free to download, with in-app purchases available.

### Which has better reviews, RST 599xp or Modal Math?

RST 599xp and Modal Math are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.

### Do RST 599xp or Modal Math have ads?

Neither RST 599xp nor Modal Math shows ads.

### Which is updated more often, RST 599xp or Modal Math?

RST 599xp ships an update every 2 months, and Modal Math every 5 weeks. Most recently, RST 599xp was updated on October 13, 2026 and Modal Math on October 8, 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.*