# splotRF vs iSmith

The clearest difference is ads: splotRF at none against iSmith's shown. splotRF also leads on monetization model (free vs ad-supported). iSmith's advantage is update cadence (every 2 days vs every 10 days) and iOS requirement (16.0 vs 18.0). On price, rating, ratings volume and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

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

splotRF ships an update every 10 days, iSmith every 2 days. The most recent releases landed on September 10, 2026 and June 6, 2026 respectively.

## The numbers

| Metric | splotRF | iSmith |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/splotrf/id1599892560/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/ismith/id6444874930/reviews) |
| Number of ratings | **2** | 1 |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 10 days | **Every 2 days** |
| Monetization | **Free** | Ad-supported |
| Size | 6 MB | 7 MB |
| Requires iOS | 18.0 | **16.0** |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [DirectRF](https://appshunter.io/developer/1572692412) | [Ryoun Chon Shin](https://appshunter.io/developer/1657565687) |

## What reviewers say

### splotRF

[App page](https://appshunter.io/ios/app/splotrf/id1599892560)

Visualize and analyze touchstone S-parameter data with interactive plots. Supports multiple file overlays, stability calculations, and various matrix conversions. Export data in vector graphics formats.

**Highlights:** Plot .snp format S-parameter data, Stability circles and µ/µ' analysis, Overlay multiple trace data, View data as a table, S/Y/Z matrix conversion, Smith Chart, Polar, and Rectangular plots, Export to PDF

**In-app purchases:** none


### 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


## Frequently asked questions

### Is splotRF free?

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

### Is iSmith free?

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

### Which has better reviews, splotRF or iSmith?

splotRF and iSmith are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.

### Do splotRF or iSmith have ads?

iSmith shows ads; splotRF does not.

### Which is updated more often, splotRF or iSmith?

splotRF ships an update every 10 days, and iSmith every 2 days. Most recently, splotRF was updated on September 10, 2026 and iSmith on June 6, 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.*