SDR vs GridCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SDR
Control compatible Icom transceivers remotely or locally from your iPad. Offers full operation, dual VFO, a logbook, and integrated digital modes like FT8/FT4, SSTV, and CW decoding.
- Remote transceiver operation
- Dual VFO and DualWatch
- Integrated logbook with ADIF support
- FT8/FT4, SSTV, and CW decoder tools
- DX-Cluster integration
- Call sign lookup and map display
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Your Icom radio on your iPad: at home over Wi-Fi or from anywhere over the internet. Made by a ham, for hams, with personal support included. SDR-Control shows the spectrum scope and waterfall of your Icom radio with all its controls on the large iPad screen. No extra hardware or software needed. WORKS WITH ■ IC-705 (Wi-Fi) ■ IC-7610, IC-7760, IC-9700, IC-7300 MK2 and the IC-R8600 receiver (radio on your network by cable) The app connects over the network only. The older IC-7300 (without MK2) has no network connection and can't be used. OPERATE ■ Spectrum scope and waterfall with band plan, DX Cluster and FT8 spots ■ Two VFOs, filters, preamp, attenuator, NB, NR, notch, AGC and more ■ Compact floating panels: tuning, PTT, CW, memories, macros, Command Bar, DTMF, RIT / ∆TX, D-Star ■ Your iPad as microphone and speaker; the radio keeps playing in the background, also with the cover closed MODES ■ FT8-Improved with AutoAnswer and AutoCQ, plus the classic FT8 ■ JS8 keyboard chat ■ CW with decoder, keyer and CW keyboard ■ Speech: incoming voice transcribed and translated, your typed text sent as speech ■ SSTV, HF-Fax, APRS and WSPR FT8-Improved, JS8, Speech and WSPR need iPadOS 26. TOOLS ■ Logbook with ADIF import and export, shared via iCloud with SmartSDR, FT-Control, TS-Control and K4-Control, on iPhone, iPad, Mac and Apple Vision Pro ■ DX Cluster, POTA, PSK Reporter, Call Lookup, Band Plan, Network Stats, Memories, Scanning, S.A.T. ■ Controllers: MIDI, CTR2, HaliKey, Pryme, Flic ■ 4O3A Genius devices and Ultra Beam antennas MADE BY A HAM Made by Marcus, DL8MRE, who has been developing apps for Apple devices since 2009 and uses this app every day in his own shack, where all supported radios are on the desk. Personal online support and a detailed manual are included. Updates with new modes and features are free: no subscription, no in-app purchases. WHAT YOU NEED ■ One of the radios above, connected to your network ■ An iPad with iPadOS 18 or later ■ For use over the internet: access to your home network from outside (see the manual) Manual: https://go-to.me/sdrcontrol-ios-manual More apps: https://ham-radio-apps.com
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.
- Visible grid for calculations
- Reverse Polish Notation (RPN)
- Incremental number entry
- Reference prior cells
- Immediate recalculation on input change
- Structured problem solving
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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
Verdict
The clearest difference is price: GridCalc at $14.99 against SDR's $49.99. GridCalc also leads on rating (5.0 vs 4.2) and review sentiment (100% vs 78%). SDR's advantage is ratings volume (70 vs 3). 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
SDR costs $49.99 and GridCalc $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.
GridCalc holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: SDR has 70 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 78% of SDR's written reviews are positive against 100% of GridCalc's.
SDR ships an update every 2 weeks, GridCalc every 4 days. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.
| Parameter | SDR | GridCalc |
|---|---|---|
| Price | $49.99 | $14.99 — better |
| Rating | 4.2 (70 ratings) | 5.0 (3 ratings) — better |
| Positive reviews | 78.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 70 — better | 3 |
| Update frequency | Every 2 weeks | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPad | iPhone, iPad — better |
| Requires iOS | 17.6 | 16.0 — better |
| Further details — not scored | ||
| Size | 55 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Marcus Roskosch | ALAN WILLIAM DIPERT |
Customer experience
SDR
GridCalc
In-app purchases
SDR
No in-app purchases
GridCalc
No in-app purchases









