Comparison

SDR vs GridCalc

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

Head to head
About

SDR

Control your Icom transceiver remotely or locally from your iPhone. Operate in all modes, log QSOs, and utilize integrated digital modes like FT8/FT4 and SSTV. No extra hardware is needed for global access.

Highlights
  • Remote transceiver operation
  • All mode control
  • Auto logging logbook
  • Integrated FT8/FT4 tool
  • Integrated SSTV receiver
  • Integrated CW decoder and keyer
  • DX-Cluster integration
Currently charting
Read full description

Software Defined Radio Client for Icom Transceivers and your iPhone SDR-Control Mobile is a full featured iPhone App to operate your Icom Transceiver at home or from around the world without additional Hard- or Software. Important: This App requires one of the following Icom Transceivers: IC-705, IC-7610, IC-9700, IC-7760 or the IC-R8600 Receiver or the new IC-7300 MK2 FACTS AND FEATURES: ■ Native iOS 26 app, backward compatible to iOS 17 ■ Compatible with any iPhone ■ Complete operation of your Icom Transceiver in all modes ■ Use the App local or to remote access of your Transceiver from any place without additional Hard- or Software ■ Logbook with auto logging, ADIF Im-/Export ■ UDP Log submission when using external logging software ■ Integrated full featured FT8 / FT4 Tool ■ Integrated SSTV receiver (NEW) ■ Integrated CW Decoder ■ Integrated CW Keyer ■ DX-Cluster integration ■ Call sign lookup integrated ■ Displays Calls on Map with heading and distance information ■ And much more... WHAT YOU NEED: - An Icom IC-705, IC-7610, IC-9700 or IC-7760 Transceiver or IC-R8600 Receiver or the new IC-7300 MK2 - The Transceiver needs to be connected to your Network (WiFi or LAN) - No USB cable needed or supported - An iPhone that runs at least iOS 17 Find out more here: https://ham-radio-apps.com Read the Manual: http://go-to.me/sdrcontrol-mobile-manual

About

GridCalc

This calculator app uses a grid interface to visualize every step of your calculations. It combines Reverse Polish Notation with a structured grid, allowing you to reference previous cells and see immediate recalculations when inputs change. Ideal for detailed, ad-hoc modeling on mobile.

Highlights
  • Visible grid for calculations
  • Reverse Polish Notation (RPN)
  • Incremental number entry
  • Reference prior cells
  • Immediate recalculation on input change
  • Structured problem solving
Features
Read full description

GridCalc is a new kind of calculator for iOS. It combines Reverse Polish Notation with a visible grid so every step of your work is structured and reviewable. Instead of a hidden stack or opaque formula bar, each value and operation lives directly in the grid. Enter numbers incrementally. Apply operations. Reference prior cells. Change any upstream input at any time and see immediate recalculation. GridCalc is built for people who think in steps and care about clarity: • Engineers and developers working through exact calculations • Finance and trading professionals modeling scenarios on the go • Students learning RPN and structured problem solving • Anyone who wants spreadsheet-level visibility without spreadsheet friction Designed for fast, ad-hoc modeling on mobile, GridCalc keeps your work visible, precise, and easy to continue later.

Screenshots

SDR4 screens
GridCalc2 screens

Verdict

The call

The clearest difference is price: GridCalc at $14.99 against SDR's $44.99. GridCalc also leads on rating (5.0 vs 4.5) and update cadence (every 4 days vs every 2 weeks). SDR's advantage is ratings volume (64 vs 2) and chart position (#173 vs unranked). On ads, in-app purchases, monetization model 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

SDR costs $44.99 and GridCalc $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

GridCalc holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: SDR has 64 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 84% of SDR's written reviews are positive against 100% of GridCalc's.

UpkeepUpdate frequency

SDR ships an update every 2 weeks, GridCalc every 4 days. The most recent releases landed on October 15, 2026 and October 1, 2026 respectively.

Scorecard6 real differences · 5 level
SDR versus GridCalc: the parameters behind the verdict, then further details
ParameterSDRGridCalc
Price$44.99$14.99 — better
Rating4.5 (64 ratings)5.0 (2 ratings) — better
Positive reviews84.1% of reviews100.0% of reviews — better
Number of ratings64 — better2
Update frequencyEvery 2 weeksEvery 4 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank#173 — better—
DevicesiPhoneiPhone, iPad — better
Requires iOS17.616.0 — better
Further details — not scored
Size47 MB5 MB
Age rating4+4+
DeveloperMarcus RoskoschALAN WILLIAM DIPERT

Customer experience

SDR

All ratings64 ratings
Positive89.1%
Neutral0.0%
Negative10.9%
Written reviews69 reviews
Positive84.1%
Neutral5.8%
Negative10.1%

GridCalc

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

SDR

Reported bugs

12 issues
  • Dialogs do not scale with larger text setting
  • Frequency display overlaps buttons
  • FT8 decoding issues (lower signal levels than WSJTX)
  • App crashes and leaves radio in transmit
  • Logbook export not functional after update
Show 7 more
  • Function button for horizontal scrolling not fully displayed
  • FT8 decode is useless and unreliable
  • Messed up radio, requiring reset
  • RX audio unusable outside home network (prior to 1.5.1)
  • Struggles with audio RX packets on remote cellular networks
  • Cannot work over mobile data with certain carriers (EE)
  • FT8 alerts sound but don't display

Requested features

14 requests
  • Develop for IC-7800
  • CarPlay support
  • Apple Watch add-on
  • Windows version
  • JS8call support
Show 9 more
  • More digital modes
  • Display memory bank names
  • Initiate memory scan from app
  • WSPR implementation
  • Tool for WSPR
  • More FT8/FT4 features (e.g., setting transmit frequency directly in FT8 view)
  • Send image to unit
  • KISS TNC support
  • Control digital modes (reflectors, etc.)

GridCalc

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

SDR

No in-app purchases

None

GridCalc

No in-app purchases

Questions

Is SDR free?
SDR costs $44.99, with no in-app purchases.
Is GridCalc free?
GridCalc costs $14.99, with no in-app purchases.
Which has better reviews, SDR or GridCalc?
GridCalc is rated higher. SDR averages 4.5 out of 5 from 64 ratings, while GridCalc averages 5.0 from 2 ratings.
Do SDR or GridCalc have ads?
Neither SDR nor GridCalc shows ads.
Which is updated more often, SDR or GridCalc?
SDR ships an update every 2 weeks, and GridCalc every 4 days. Most recently, SDR was updated on October 15, 2026 and GridCalc on October 1, 2026.

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