Radio ID vs rtl_tcp SDR
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Radio ID
This utility decodes two-way radio transmissions using industry-standard formats like Motorola MDC-1200, GE STAR, and Kenwood FleetSync. It also supports QuickCall II signaling, making it an essential tool for radio technicians and scanner enthusiasts.
- Decodes Motorola MDC-1200
- Decodes GE STAR
- Decodes Kenwood FleetSync
- Decodes QuickCall II signaling
- Useful for radio technicians
- Helpful for scanner listeners
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Identify two-way radio transmissions made using Motorola MDC-1200, GE STAR, or Kenwood FleetSync radio identifier formats. Also decodes QuickCall II signaling format. (All formats trademarks of their respective owners). Invaluable tool for the two-way radio technician and a helpful utility for the serious scanner listener.
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.
Screenshots
Verdict
The clearest difference is price: Radio ID at $0.99 against rtl_tcp SDR's $12.99. Radio ID also leads on review sentiment (64% vs 40%). rtl_tcp SDR's advantage is rating (3.9 vs 3.7). On ratings volume, update cadence, ads and in-app purchases 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
Radio ID costs $0.99 and rtl_tcp SDR $12.99 up front. Neither carries in-app purchases, so what you see is what you pay.
rtl_tcp SDR holds the better App Store score, 3.9 against 3.7. Both are backed by a comparable volume of ratings — 46 and 32 respectively. Written reviews complicate that: 64% of Radio ID's written reviews are positive against 40% of rtl_tcp SDR's, so the app with the better star average is not the one people write more warmly about.
Radio ID ships an update every 7 months, rtl_tcp SDR every 4 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.
| Parameter | Radio ID | rtl_tcp SDR |
|---|---|---|
| Price | $0.99 — better | $12.99 |
| Rating | 3.7 (46 ratings) | 3.9 (32 ratings) — better |
| Positive reviews | 64.3% of reviews — better | 40.0% of reviews |
| Number of ratings | 46 — better | 32 |
| Update frequency | Every 7 months | Every 4 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 16.0 — better | 16.6 |
| Further details — not scored | ||
| Size | 1 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Matthew Kaufman | HotPaw Productions |
Customer experience
Radio ID
rtl_tcp SDR
In-app purchases
Radio ID
No in-app purchases
rtl_tcp SDR
No in-app purchases
