rtl_tcp SDR vs SDR
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
rtl_tcp SDR
This app acts as a software-defined radio receiver for iOS devices, allowing you to listen to various radio signals and view RF spectrum data. It connects to external SDR peripherals via a network protocol, requiring a separate server setup.
- Listen to AM, FM, SSB, CW signals
- View RF spectrum and waterfall
- Connect to networked RTL-SDR peripherals
- Supports Airspy HF+, SDRPlay, LimeSDR Mini
- Direct connection to Hermes Lite 2
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An RTL-SDR Software Defined Radio receiver app for iOS devices. Listen to AM, FM, SSB and CW radio signals. View an RF spectrum and waterfall. Connect, via the rtl_tcp network protocol, to networked RTL-SDR USB peripherals. This app requires an external rtl_tcp server. iOS devices do not currently support the direct connection of USB peripherals such as an RTL-SDR. Thus, the use of this app requires network access to a server, such as a Raspberry Pi (or Mac), with an RTL-SDR unit plugged into its USB port, and running the rtl_tcp protocol at an TCP/IP network address accessible from your iOS device. This allows a Raspberry Pi (or Mac) to act, essentially, as the USB port adapter for your iOS device. The rtl_tcp SDR app can also connect to hfp_tcp for the Airspy HF+, rsp_tcp for SDRPlay devices, and lmm_tcp for the LimeSDR Mini; see GitHub for server source code. This app can also connect to a Hermes Lite 2 QRP transceiver directly, if it has a known IP address, or through an hl2_tcp server. No support is provided for installing any of the rtl_tcp or other tcp software needed to use this app (with a Raspberry Pi, or otherwise). Please do not download this app unless you are already familiar with Software Defined Radio, have an RTL-SDR or equivalent USB SDR peripheral, and have already installed and tested rtl_tcp on your Raspberry Pi, Mac, or other server. Note that this app requires a very high bandwidth network connection in order to receive streams of real-time RF samples from an RTL-SDR. It is recommended that your rtl_tcp server be on a wired connection rather than on the same WiFi as your iOS device.
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.
- Remote transceiver operation
- All mode control
- Auto logging logbook
- Integrated FT8/FT4 tool
- Integrated SSTV receiver
- Integrated CW decoder and keyer
- DX-Cluster integration
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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
Screenshots
Verdict
The clearest difference is price: rtl_tcp SDR at $12.99 against SDR's $44.99. SDR's advantage is review sentiment (84% vs 40%) and rating (4.5 vs 3.9). On ratings volume, ads, in-app purchases and monetization model 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
rtl_tcp SDR costs $12.99 and SDR $44.99 up front. Neither carries in-app purchases, so what you see is what you pay.
SDR holds the better App Store score, 4.5 against 3.9. Both are backed by a comparable volume of ratings — 32 and 64 respectively. Written reviews point the same way: 40% of rtl_tcp SDR's written reviews are positive against 84% of SDR's.
rtl_tcp SDR ships an update every 4 months, SDR every 2 weeks. The most recent releases landed on September 16, 2026 and September 24, 2026 respectively.
| Parameter | rtl_tcp SDR | SDR |
|---|---|---|
| Price | $12.99 — better | $44.99 |
| Rating | 3.9 (32 ratings) | 4.5 (64 ratings) — better |
| Positive reviews | 40.0% of reviews | 84.1% of reviews — better |
| Number of ratings | 32 | 64 — better |
| Update frequency | Every 4 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | #197 | #136 — better |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 16.6 — better | 17.6 |
| Further details — not scored | ||
| Size | 3 MB | 47 MB |
| Age rating | 4+ | 4+ |
| Developer | HotPaw Productions | Marcus Roskosch |
Customer experience
rtl_tcp SDR
SDR
Bugs and requests
rtl_tcp SDR
Not enough reviews yet to summarise bugs or 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 moreShow fewer
- 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 moreShow fewer
- 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.)
In-app purchases
rtl_tcp SDR
No in-app purchases
SDR
No in-app purchases








