splotRF vs iSmith
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
splotRF
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.
- 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
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Key Features: • plots .snp format s-parameter touchstone data • stability circles for load and source • µ and µ' for load and source stability • interactive data markers • overlay multiple trace data on a single plot • overlay trace data from multiple files • view data as a table list • arbitrary number of ports (.s1p, .s2p, s3p…snp support) • S/Y/Z matrix conversion • mA/RI/dB formatting • interpolation over frequency • exports vector graphics to .pdf • plotting display properties and configuration are saved within file comments • automated grid layout • Smith Chart, Polar and Rectangular plots • reads and plots .zip archives containing s-parameter data
iSmith
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.
- 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
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Features: - Read out Z, Y, VSWR, Q and Gamma from smith chart. - Calculate 8 L-matching networks. - Set matching target by touching smith chart. - Calculate T & Pi matching pad. - Learn the principle of impedance matching. - dBm, Watts and Volts conversion - VSWR Conversion
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | splotRF | iSmith |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) | 5.0 (1 ratings) |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 10 days | Every 2 days — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, Mac — better | iPhone, iPad |
| Requires iOS | 18.0 | 16.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | DirectRF | Ryoun Chon Shin |
Customer experience
splotRF
iSmith
In-app purchases
splotRF
No in-app purchases
iSmith
No in-app purchases
