# iSmith vs RF toolbox

The clearest difference is in-app purchases: iSmith at none against RF toolbox's 1. iSmith also leads on update cadence (every 2 days vs every 6 months). RF toolbox's advantage is ads (none vs shown) and iOS requirement (13.0 vs 16.0). On price and device support there is nothing between them.

Both are free to download. RF toolbox sells 1 one-off in-app purchase. iSmith asks for nothing beyond the download.

iSmith ships an update every 2 days, RF toolbox every 6 months. The most recent releases landed on September 21, 2026 and September 27, 2026 respectively.

## The numbers

| Metric | iSmith | RF toolbox |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/ismith/id6444874930/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 2 days** | Every 6 months |
| Monetization | Ad-supported | — |
| Size | 7 MB | 28 MB |
| Requires iOS | 16.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Ryoun Chon Shin](https://appshunter.io/developer/1657565687) | [Anas Abubakar](https://appshunter.io/developer/1581534101) |

## What reviewers say

### iSmith

[App page](https://appshunter.io/ios/app/ismith/id6444874930)

This app helps users understand impedance matching principles. It allows for reading key network parameters from a Smith chart and calculating various matching networks and pads. Users can also convert between different power and voltage units.

**Highlights:** Read Smith chart parameters (Z, Y, VSWR, Q, Gamma), Calculate 8 L-matching networks, Calculate T & Pi matching pads, Set matching targets on Smith chart, Learn impedance matching principles, dBm, Watts, and Volts conversion, VSWR conversion

**Features:** macOS Compatibility

**In-app purchases:** none


### RF toolbox

[App page](https://appshunter.io/ios/app/rf-toolbox-electronics/id6757265018)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| upgrade to pro | $3.99 | one-time |


## Frequently asked questions

### Is iSmith free?

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

### Is RF toolbox free?

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

### Do iSmith or RF toolbox have ads?

iSmith shows ads; RF toolbox does not.

### Which is updated more often, iSmith or RF toolbox?

iSmith ships an update every 2 days, and RF toolbox every 6 months. Most recently, iSmith was updated on September 21, 2026 and RF toolbox on September 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.*