Comparison

iSmith vs RF toolbox

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

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
Read full description

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

About

RF toolbox

Features
Read full description

RF Toolbox — All-in-One RF Engineering Calculator & Design Suite RF Toolbox is a practical, field-ready app built for RF engineers, students, and radio hobbyists who need fast, reliable calculations and design utilities in one place. From impedance matching and transmission line work to filter and attenuator synthesis, RF Toolbox helps you move from idea to implementation with less friction. KEY FEATURES Impedance & S-Parameter Tools • Smith Chart utilities for impedance visualization and matching workflows • S11 parameter / reflection analysis support • Reflection coefficient and VSWR calculators Matching Networks • L, Pi (π), and T matching network calculators • Stub tuner tools for transmission-line matching • Filters (Passive & RF) • RC and RL passive filter calculators • LC low-pass prototypes: Butterworth and Chebyshev (up to 8th order) • Microstrip filters: band-pass and band-reject (notch) • RLC Networks • RLC series and parallel calculators for resonance and frequency behavior Attenuators • Pi (π), T, and Bridge-T attenuator calculators for common RF pad designs • Cascaded Networks • Cascaded network calculations for chained RF blocks and stages Antenna & Propagation • Antenna design utilities (core RF design helpers) • Path loss calculators • Friis link budget calculator • Power density calculator • Radar maximum range calculator Component Toolkits • Inductor design: air-core, spiral, and multi-layer air-core • Resistors: SMD code, color code, and series/parallel network calculator • Capacitors: SMD code and series/parallel network calculator DESIGNED FOR SPEED AND ACCURACY RF Toolbox is organized for quick access—open the tool you need, enter values, and get results immediately. Whether you’re prototyping a matching network, checking VSWR, sizing an attenuator, or running a quick link budget, RF Toolbox keeps your workflow efficient. Download RF Toolbox and keep essential RF design tools in your pocket.

Screenshots

iSmith4 screens
RF toolbox4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

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

Scorecard4 real differences · 5 level
iSmith versus RF toolbox: the parameters behind the verdict, then further details
ParameteriSmithRF toolbox
PriceFreeFree
Rating5.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyEvery 2 days — betterEvery 6 months
AdsYesNo — better
In-app purchasesNo — betterYes
MonetizationAd-supported—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.013.0 — better
Further details — not scored
Size7 MB28 MB
Age rating4+4+
DeveloperRyoun Chon ShinAnas Abubakar

In-app purchases

None

iSmith

No in-app purchases

1 purchases

RF toolbox

One-time1
  • upgrade to pro$3.99

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 June 6, 2026 and RF toolbox on September 27, 2026.

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