# RST Scope vs RF Calc JP

The clearest difference is in-app purchases: RST Scope at none against RF Calc JP's 1. RST Scope also leads on update cadence (every 3 days vs every 6 days) and iOS requirement (15.6 vs 26.0). RF Calc JP's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. RF Calc JP sells 1 in-app purchase, starting at $0.99 per year. RST Scope asks for nothing beyond the download.

RST Scope ships an update every 3 days, RF Calc JP every 6 days. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | RST Scope | RF Calc JP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rst-scope/id1550582276/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 3 days** | Every 6 days |
| Monetization | Ad-supported | — |
| Size | 5 MB | 4 MB |
| Requires iOS | **15.6** | 26.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [koji kamogawa](https://appshunter.io/developer/1488210713) | [Hashimoto Yoshikazu](https://appshunter.io/developer/6790925881) |

## What reviewers say

### RST Scope

[App page](https://appshunter.io/ios/app/rst-scope/id1550582276)

This utility app provides spectrum scope and waterfall displays for amateur radio operators. It enhances radios lacking these features by analyzing microphone input, allowing for clear distinction of Morse code and detailed audio frequency visualization.

**Highlights:** Spectrum scope and waterfall display, Morse code distinction via FFT, Adjustable waterfall speed, Adjustable audio input level, Switchable display band (wide/narrow), Display pause function, Recording and playback of input sound

**In-app purchases:** none


### RF Calc JP

[App page](https://appshunter.io/ios/app/rf-calc-jp/id6815598081)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RF Calc JP Pro (Yearly) | $0.99 | per year |


## Frequently asked questions

### Is RST Scope free?

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

### Is RF Calc JP free?

RF Calc JP is free to download, with in-app purchases available.

### Do RST Scope or RF Calc JP have ads?

RST Scope shows ads; RF Calc JP does not.

### Which is updated more often, RST Scope or RF Calc JP?

RST Scope ships an update every 3 days, and RF Calc JP every 6 days. Most recently, RST Scope was updated on November 3, 2026 and RF Calc JP 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.*