# rtl_tcp SDR — RTL-SDR Software Defined Radio > iOS SDR receiver connecting to external USB SDR peripherals via network protocol. (iPhone/iPad app by HotPaw Productions.) - Source: https://appshunter.io/ios/app/rtl-tcp-sdr/id1351164646 (this page in markdown: same URL + `.md`) - Developer: [HotPaw Productions](https://appshunter.io/developer/285074853) - Category: Utilities, Education - Price: $12.99 (on sale, was $19.99) - Rating: 3.90/5 from 32 App Store ratings · 30 written reviews indexed - Age rating: 4+ - Requires: iOS 16.6 · 3 MB - Languages: American English - Released: 2018-05-02 - Data updated: 2026-08-29 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/rtl-tcp-sdr/id1351164646/reviews.md ## What is rtl_tcp SDR? 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. ## Key features - 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 ## Recent user reviews (10 of 30) All indexed reviews: https://appshunter.io/ios/app/rtl-tcp-sdr/id1351164646/reviews.md ### 5/5 — Works well *2025-11-21* I have an RTL-SDR blog v4 connected to a fedora 43 server that I’m running rtl_tcp on. This app is working really well on both my iPhone and iPad, connecting to rtl_tcp. Sounds great and was easy to connect. Would love to see the ability to save and scan channels in this app. Would also be awesome to be able to scan a frequency range. ### 4/5 — Solution for Hermes Lite or SDRPlay! *2025-09-25* It isn’t perfect but it really cool to be able listen and even transmit using my Hermes Lite HF rig from anywhere! I think there’s a memory leak or some issue because after a few minutes and several transmissions it starts having issues. But I’m sure that will get fixed eventually. Nice job! ### 5/5 — Works great *2025-07-28* Simple, basic remote sdr receiver/ controller- even has a built-in up converter setting. Waterfall looks good lots of different demodulation options. Highly recommend. It’s not some incredibly fancy software, but it does exactly what it says it does. Pretty amazing with apples limitations. Surprising how well it works no frills SDR receiver. ### 4/5 — It could be good in a certain way *2025-03-21* Since there’s so many things that I need to do to actually make it work since you have to plug it into something by the way, I need extra ways for this to work and it’s pretty complicated and stuff so I need some extra things for it to work properly that you can go up to one gigahertz I think I’m trying to find the perfect SDR that doesn’t require such complicated stuff like plugging it in ### 5/5 — Great little app!! *2024-12-25* I use this to connect to a pi with SDR I have across the yard on top of my outbuilding, fiber backbone connects that building to my home network. It works like a champ! I can sit on the couch with my iPad or phone and listen or sniff out noise away from the radio room… thanks! ### 3/5 — Oops *2024-08-05* Downloaded then deleted once I saw the setup requirements. Refund possible? Thanks, Eric KC1OAV ### 2/5 — Works *2024-02-29* Works, interface is terrible, cannot slide back without retuning half a frame, can slide forward any before retuning, fix this please!!! ### 3/5 — Ok it looks like you did not fix the memory save process *2023-02-20* Please fix the memory save process. Also please add more memories.. ### 3/5 — Needs improvement *2023-02-19* This is the best SDR app for iOS but needs improvement. The main interface and settings interfaces are clunky and need a redesign, and the limitation of only 5 presets is ludicrous. There should be so many more, with the ability to store frequencies in bands or lists with station ID, modulation, date and time stamp etc. This app could be so good but is only very rarely updated. I have two other stars waiting for this one… ### 1/5 — Does not work *2022-12-12* I understand how to set up and operate these programs. Though, this one fails. Back to my android app. ## Frequently asked questions about rtl_tcp SDR ### What does this app do? This app functions as a software-defined radio receiver for iOS devices. It allows you to tune into various radio signals like AM, FM, SSB, and CW, and visualize the radio frequency spectrum and waterfall displays. It connects to external SDR hardware through a network protocol. ### How do I connect an SDR peripheral to this app? This app requires an external rtl_tcp server to connect to USB SDR peripherals. iOS devices cannot directly connect USB devices. You need to set up a server, such as a Raspberry Pi or Mac, with the SDR plugged in and running the rtl_tcp protocol, accessible over your network. ### What are the costs associated with using this app? The app itself is a paid application. However, it requires an external SDR peripheral and a separate server setup, which may incur additional hardware and software costs depending on your existing equipment and chosen server solution. ### What devices is this app compatible with? This app is designed for iOS devices. It can connect to various SDR peripherals like RTL-SDR, Airspy HF+, SDRPlay devices, LimeSDR Mini, and Hermes Lite 2, provided they are connected to a compatible network server. ### What are the typical use cases for this app? This app is ideal for radio enthusiasts and hobbyists interested in exploring radio frequencies. It can be used for listening to shortwave broadcasts, amateur radio communications, monitoring radio spectrum activity, and learning about radio signal analysis. ## Version history (last 5 releases) ### 1.5.6 — 2026-01-21 Stability enhancements and minor bug fixes for SSB modulation and CW decoding. ### 1.5.5 — 2025-04-24 Bug fixes for HL2 PTT/keying. ### 1.5.4 — 2025-03-21 Bug fixes and stability enhancements. Improved support for Hermes Lite 2 CW & SSB transmit. Added support for the CTR2 MIDI control knob. ### 1.5.3 — 2024-12-29 Bug fixes and stability enhancements ### 1.5.2 — 2024-05-15 Stability enhancements and Bug fixes (FM audio spectrum, SSB, noise reduction, and audio limiter) ## Apps similar to rtl_tcp SDR | App | Rating | Price | Category | | --- | --- | --- | --- | | [レコーダー - スピークバディ パーソナルコーチング](https://appshunter.io/ios/app/id1469874020) | — | Free | Utilities | | [小灵龙App](https://appshunter.io/ios/app/app/id1221738240) | 1.0 (12) | Free | Utilities | | [Rule of Three Calculator](https://appshunter.io/ios/app/rule-of-three-calculator/id1185318300) | 2.3 (4) | Free | Utilities | | [TLF Events Tamil](https://appshunter.io/ios/app/tlf-events-tamil/id1481109080) | — | Free | Utilities | | [SSI Steel Design](https://appshunter.io/ios/app/ssi-steel-design/id1474838160) | 3.0 (1) | Free | Utilities | | [JEDA Live 職達](https://appshunter.io/ios/app/jeda-live/id1476523220) | — | Free | Utilities | ## More apps by HotPaw Productions - [inTuna Strobe Guitar Tuner](https://appshunter.io/ios/app/intuna-strobe-guitar-tuner/id285074850) - [Sing-inTuna](https://appshunter.io/ios/app/sing-intuna/id294767812) - [HotPaw Basic](https://appshunter.io/ios/app/hotpaw-basic/id295464266) - [MorseTest](https://appshunter.io/ios/app/morsetest/id297010360) - [XOCubed (3D Tic Tac Toe)](https://appshunter.io/ios/app/xocubed-3d-tic-tac-toe/id303500525) - [iAutoharp](https://appshunter.io/ios/app/iautoharp/id304091719) All apps by HotPaw Productions: https://appshunter.io/developer/285074853 ## Related topics [echo sdr](https://appshunter.io/ios/topics/echo-sdr) · [rtl sdr](https://appshunter.io/ios/topics/rtl-sdr) · [sdr touch](https://appshunter.io/ios/topics/sdr-touch) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*