Comparison

iSDR vs SatNOGS

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

Head to head
About

iSDR

This app allows experimenters and amateur radio enthusiasts to build a portable software-defined radio receiver using their iOS device. It processes radio signals using the device's processor and offers various display and filtering modes. Additional hardware is required for live signal reception.

Highlights
  • Six receive mode settings (USB, LSB, CW, AM, FM, Binaural)
  • Selectable bandwidth settings
  • 120 dB dynamic range signal strength meter
  • Three AGC settings (fast, slow, off)
  • Spectrum, Waterfall, and Oscilloscope display modes
  • Supports downloaded audio-format spectrum files via iTunes
  • Embed center frequency in file names for automatic display
Features
Read full description

PLEASE READ THE ENTIRE DESCRIPTION BEFORE PURCHASING. iSDR is the first and only software-defined radio application compatible with the Apple iPhone®, iPod touch® and iPad™. iSDR is for experimenters and amateur radio enthusiasts looking to construct a truly portable software-defined radio receiver. Additional hardware is required to receive live signals. Currently, iOS devices will not work with RTL-SDR USB dongles, and they are not supported by iSDR. PLEASE NOTE: Receiving live on-air signals using iSDR requires purchasing or constructing a "quadrature sampling detector (QSD)" RF front-end device, and connecting it between an antenna and the microphone input jack. Alternatively, iSDR can be used to implement a panadapter for use with a compatible radio receiver. Without a QSD RF front-end or a connected radio, iSDR will only play I/Q recordings of actual radio signals. Additional recordings can be loaded into the app using iTunes file sharing - some recordings are available free to download from the Internet. Visit the support web site for more information. iSDR includes a sample I/Q recording featuring 30 seconds of a ham radio contest. This is for demonstration purposes only. It is not meant to fool you! It is to allow you to experience how the app works without having to do anything yourself: just turn it on. You can download and play your own files if you like. Please see the support page for details. AND PLEASE contact us directly if you experience any issues with using this app. We will respond promptly when provided with details. When iSDR is used to receive live radio signals, receiver performance will depend largely on the quadrature sampling detector and antenna that you use. iSDR is a software-defined receiver application for use on mobile handset devices and iPad. Despite its extreme portability, the app utilizes the same digital signal processing techniques found in PC-based SDR receivers. It does frequency domain filtering using a theoretical "brick wall" sinc filter algorithm to provide steep and deep bandpass filtering. iSDR doesn't utilize any DSP hardware but instead uses the iOS device's processor to implement DSP algorithms. Features o Six receive mode settings: USB, LSB, CW, AM, FM* and Binaural. o Selectable bandwidth settings for each mode. o Signal strength meter covering 120 dB of dynamic range with peak and average power indication. o Three AGC settings: fast, slow, and off. o Three display modes: Spectrum, Waterfall and Oscilloscope. o File sharing** supports downloaded audio-format spectrum files synced using iTunes. o Most PCM file formats are supported, including .wav and .caf. o Embed the center frequency in your file names and iSDR will automatically display the correct frequency! o Tune quickly using a single touch to the display screen, or tune precisely using the rainbow tune bar. o Change radio settings with a simple double-tap action to the red cursor, mode text, AGC indicator or signal grid! o Up to 44.1 kHz of available spectrum bandwidth. o Dimmable semi-log or linear spectrum grid (native Settings app only). o Adjustable CW offset (native Settings app only). o Monaural microphone input automatically adjusts the display to 22 kHz bandwidth. o Automatically detects if external audio is available for receiving live signals (menu selectable). o Reverse I/Q stereo input logic (menu selectable). *FM mode is not supported for monaural signals, and will not appear as a mode selection unless stereo audio (live or recorded) is available. Narrowband FM only: 16 kHz or 11.2 kHz bandwidth. Please contact Digital Confections with your questions and suggestions!

About

SatNOGS

Access a global network of satellite ground stations to communicate with satellites and observe their data. The platform is open to all, with public observation results freely distributed. Resources are available for building your own ground station.

Highlights
  • Global ground station network access
  • Remote ground station operation
  • Satellite communication
  • Public observation data access
  • Ground station building resources
Read full description

SatNOGS Network is a global management interface to facilitate multiple ground station operations remotely. An observer is able to take advantage of the full network of SatNOGS ground stations around the world. The network is open to anyone. Any observer is able to utilize all available Ground Stations and communicate with Satellites. All observations results are public and all data are distributed freely under the Creative Commons Atribution-Share Alike license. Whether you own satellite ground station equipment or you want to build one you can head to SatNOGS Project site to get up to date documentation and info on how to build a SatNOGS ground station. App functionality is currently limited by SatNOGS API and will be significantly improved in next major release.

Screenshots

iSDR4 screens
SatNOGS4 screens

Verdict

The call

The clearest difference is price: SatNOGS at Free against iSDR's $0.99. SatNOGS also leads on rating (5.0 vs 2.5) and in-app purchases (none vs 1). iSDR's advantage is iOS requirement (9.0 vs 15.0). On ratings volume, update cadence, ads 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

SatNOGS is free to download; iSDR costs $0.99 up front. iSDR sells 1 one-off in-app purchase. SatNOGS asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

SatNOGS holds the better App Store score, 5.0 against 2.5. Both are backed by a comparable volume of ratings — 11 and 4 respectively.

UpkeepUpdate frequency

iSDR ships an update every 3 months, SatNOGS every 5 months. The most recent releases landed on October 4, 2026 and October 1, 2026 respectively.

Scorecard5 real differences · 5 level
iSDR versus SatNOGS: the parameters behind the verdict, then further details
ParameteriSDRSatNOGS
Price$0.99Free — better
Rating2.5 (11 ratings)5.0 (4 ratings) — better
Positive reviews51.7% of reviews—
Number of ratings11 — better4
Update frequencyEvery 3 months — betterEvery 5 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.0 — better15.0
Further details — not scored
Size36 MB48 MB
Age rating4+4+
DeveloperDigital Confections LLCVictor Belov

Customer experience

iSDR

All ratings11 ratings
Positive36.4%
Neutral0.0%
Negative63.6%
Written reviews58 reviews
Positive51.7%
Neutral12.1%
Negative36.2%

SatNOGS

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

iSDR

One-time1
  • Wi-Fi Radio ControlFree
None

SatNOGS

No in-app purchases

Questions

Is iSDR free?
iSDR costs $0.99, and also offers in-app purchases.
Is SatNOGS free?
SatNOGS is free to download, with no in-app purchases.
Which has better reviews, iSDR or SatNOGS?
SatNOGS is rated higher. iSDR averages 2.5 out of 5 from 11 ratings, while SatNOGS averages 5.0 from 4 ratings.
Do iSDR or SatNOGS have ads?
Neither iSDR nor SatNOGS shows ads.
Which is updated more often, iSDR or SatNOGS?
iSDR ships an update every 3 months, and SatNOGS every 5 months. Most recently, iSDR was updated on October 4, 2026 and SatNOGS on October 1, 2026.

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