Comparison

RST Scope vs RF Engineer Toolkit

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

Head to head
About

RST Scope

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
Read full description

This is an app for amateur radio operators with a narrow band of audio frequency, spectrum scope & waterfall display. You can get a rich display by microphone inputting the speaker output of a radio that does not have a spectrum scope or waterfall function. The FFT allows you to distinguish between the dot and dash of Morse code. [function] 1. Ability to change the speed of the waterfall 2. Ability to adjust the level of audio input 3. Function to switch the display band between wide and narrow 4. Display pause function (pause / cancel by touching the screen) 5. Function to switch the cross hatch ON / OFF by longTap 6. Frequency resolution is fixed at 40Hz. 7. Function to switch the USB/LSB by Left/Right Swipe 8.Recording/Playback function of Input Sound RST Scope(Free) https://www.youtube.com/watch?v=1s9RvOFp52g

About

RF Engineer Toolkit

This app provides a comprehensive suite of 45 RF and antenna calculators for engineers and technicians. It offers unit-tested formulas for field, site, and lab calculations, including RF exposure and impedance matching. A free version offers 16 calculators, with Pro unlocking all features and advanced options.

Highlights
  • 45 RF and antenna calculators
  • Unit-tested formulas against industry standards
  • Field and site calculations (VSWR, link budget, RF exposure)
  • Design and lab calculations (Smith chart, impedance matching, filters)
  • Everyday RF conversions (dBm, W, V)
  • Free version with 16 calculators
  • Pro version with full access and advanced features
Features
Read full description

RF Engineer Toolkit is the calculator set RF engineers, tower and DAS technicians, PCB designers, and radio amateurs reach for every day. 45 calculators, every formula unit-tested against Pozar, Balanis, ICNIRP 2020, FCC OET-65, and manufacturer cable data — with live results, locale-aware input, and no ads. FIELD AND SITE • VSWR, return loss, reflection coefficient, and mismatch loss from any one value or a wattmeter reading. • Cable loss with manufacturer coefficients (LMR, RG, Heliax, 9913), SWR loss, and ERP. • Link budget with FSPL, cable losses, gains, sensitivity, and margin. • Antenna downtilt and coverage, radio horizon, Fresnel zone with earth bulge and clearance. • RF exposure against FCC and ICNIRP limits, with safe distance for public and occupational exposure. • Antenna separation and co-site isolation, including required spacing. • Dipole, helical, and parabolic dish design, near-field boundaries, and Doppler shift. DESIGN AND LAB • Smith chart with series and shunt elements, lines and stubs, exportable as an image. • Impedance matching networks (L, Pi, T) with Q and bandwidth. • Attenuators (Pi, Tee, bridged-T, L-pad) with E24 and E96 values and real achieved attenuation. • LC filter designer: Butterworth and Chebyshev, low-pass, high-pass, band-pass, and band-stop. • Receiver chain: cascaded gain, noise figure, IP3, noise floor, and SFDR. • Amplifier linearity: P1dB, IP3, back-off, IM3, and PAE. • Microstrip, stripline, coplanar, and differential-pair impedance with synthesis and substrate presets. • Coax impedance, cable delay and phase, quarter-wave transformers, and skin depth. • Power dividers and directional couplers, S-parameter conversion, and intermodulation products. • Rectangular and circular waveguides with WR tables, cutoff, and guide wavelength. EVERYDAY CALCULATORS • dBm, dBW, W, V, dBV, dBµV, dBu, and dBi/dBd conversion. • Wavelength, reactance, resonance, time constants, Ohm's law, dividers, series and parallel circuits. FREE AND PRO 16 calculators are free, and every Pro calculator can be previewed. RF Toolkit Pro unlocks: • All 45 RF calculators. • Searchable calculation history with saved inputs. • PDF exports of calculation result sheets. • Custom cable and substrate libraries. Choose the plan that works for you: • Yearly subscription with a 7-day free trial. • Monthly subscription. • One-time lifetime purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the current period ends. You can manage subscriptions in your Apple Account settings. PRIVACY No accounts. No analytics. No ads. No tracking. Your calculation history stays on your device. Privacy Policy: https://zhsystems.me/privacy-rf-engineer-toolkit-privacy-policy-terms-of-use/ Terms of Use: https://zhsystems.me/turms-rf-engineer-toolkit-terms-of-use/

Screenshots

RST Scope3 screens
RF Engineer Toolkit4 screens

Verdict

The call

The clearest difference is in-app purchases: RST Scope at none against RF Engineer Toolkit's 3. RST Scope also leads on update cadence (every 3 days vs every 2 months) and iOS requirement (15.6 vs 17.6). RF Engineer Toolkit's advantage is ads (none vs shown). On price, rating, ratings volume 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 Engineer Toolkit sells 3 in-app purchases, starting at $0.99 per month. RST Scope asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for RST Scope against 5.0 for RF Engineer Toolkit. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

UpkeepUpdate frequency

RST Scope ships an update every 3 days, RF Engineer Toolkit every 2 months. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

Scorecard5 real differences · 5 level
RST Scope versus RF Engineer Toolkit: the parameters behind the verdict, then further details
ParameterRST ScopeRF Engineer Toolkit
PriceFreeFree
Rating5.0 (1 ratings)5.0 (1 ratings)
Positive reviews—0.0% of reviews
Number of ratings11
Update frequencyEvery 3 days — betterEvery 2 months
AdsYesNo — better
In-app purchasesNo — betterYes
MonetizationAd-supported — betterFreemium
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.6 — better17.6
Further details — not scored
Size5 MB12 MB
Age rating4+4+
Developerkoji kamogawaVladislav Zhirnov

Customer experience

RST Scope

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

RF Engineer Toolkit

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

RST Scope

No in-app purchases

3 purchases

RF Engineer Toolkit

Subscriptions2
  • Full version / monthly$0.991 Month
  • Full version / year$4.991 Year
One-time1
  • Remove ADS$9.99

Questions

Is RST Scope free?
RST Scope is free to download, with no in-app purchases.
Is RF Engineer Toolkit free?
RF Engineer Toolkit is free to download, with in-app purchases available.
Which has better reviews, RST Scope or RF Engineer Toolkit?
RST Scope and RF Engineer Toolkit are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.
Do RST Scope or RF Engineer Toolkit have ads?
RST Scope shows ads; RF Engineer Toolkit does not.
Which is updated more often, RST Scope or RF Engineer Toolkit?
RST Scope ships an update every 3 days, and RF Engineer Toolkit every 2 months. Most recently, RST Scope was updated on November 3, 2026 and RF Engineer Toolkit on November 5, 2026.

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