# Spectrum SDR (RTL-SDR) — Software Defined Radio

> Software Defined Radio (iPhone/iPad app by James Mainwaring.)

- Source: https://appshunter.io/ios/app/spectrum-sdr-rtl-sdr/id6764391865 (this page in markdown: same URL + `.md`)
- Developer: [James Mainwaring](https://appshunter.io/developer/1895761181)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.0 · 7 MB
- Languages: American English
- Released: 2026-05-05
- Data updated: 2026-08-08
- User reviews in markdown: https://appshunter.io/ios/app/spectrum-sdr-rtl-sdr/id6764391865/reviews.md

## What is Spectrum SDR (RTL?

This application is about having a bit of fun with those amazing little RTL-SDR dongles, whilst listening to AM/FM/SSB/CW radio signals. It's nice and easy to use so why not give it a try?

- Covers the full frequency range of your RTL-SDR dongle.
- AM and FM, wide and narrow, SSB, CW.
- FFT and Waterfall displays.
- Sample rates 240000 Hz to 2160000 Hz.
- Bias tee control.
- 75 presets over 5 pages.
- Gain controls.
- Squelch.
- Flexible display options, hide things you don't need to see.
- Built-in help.

The application needs to be connected to an instance of rtl_tcp running on a remote computer, most likely over WiFi. You will need a good network connection for this to work reliably when using the higher sample rates.

It can be installed on an iPhone, iPad or Apple Silicon Mac.

We hope you enjoy using this application.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Full Version | $2.99 | one-time |



## Version history (last 5 releases)

### 1.8 — 2026-08-06

Fix squelch problem preventing it silencing audio when screen is blanked.

### 1.7 — 2026-07-25

Add new button to toolbar to allow frequency to be entered and fix bug where too many controls were hidden when hiding level meters.

### 1.6 — 2026-07-14

- FFT has central red line to clearly indicate the tuned frequency.
- FFT has a shaded region showing the extent of the current demodulator's filter.
- Zoom feature and adjustable tuning rate give improved user experience, particularly when tuning to very narrow signals.

### 1.5 — 2026-06-19

Now has a CW demodulator to receive Morse code.

### 1.4 — 2026-05-18

Use a bar graph instead of a line graph for FFT view.

## Related topics

[sdr touch](https://appshunter.io/ios/topics/sdr-touch) · [rtl sdr](https://appshunter.io/ios/topics/rtl-sdr) · [echo sdr](https://appshunter.io/ios/topics/echo-sdr)

---

*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 2026-08-08.*