# rtl_tcp SDR vs smartDF

The clearest difference is price: smartDF at Free against rtl_tcp SDR's $12.99. smartDF also leads on update cadence (weekly vs every 4 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

smartDF is free to download; rtl_tcp SDR costs $12.99 up front. Neither carries in-app purchases, so what you see is what you pay.

rtl_tcp SDR ships an update every 4 months, smartDF weekly. The most recent releases landed on October 23, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | rtl_tcp SDR | smartDF |
| --- | --- | --- |
| Price | $12.99 | **Free** |
| Rating | **[3.9 (32 ratings)](https://appshunter.io/ios/app/rtl-tcp-sdr/id1351164646/reviews)** | — |
| Number of ratings | **32** | — |
| Positive reviews | 40.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | Paid | — |
| Size | 3 MB | 59 MB |
| Requires iOS | 16.6 | **15.4** |
| Devices | **iPhone, iPad** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [HotPaw Productions](https://appshunter.io/developer/285074853) | [Carlos Yordanis Lago Gonzalez](https://appshunter.io/developer/1028936188) |

## What reviewers say

### rtl_tcp SDR

[App page](https://appshunter.io/ios/app/rtl-tcp-sdr/id1351164646)

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.

**Highlights:** 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

**Features:** Vision Pro support

**In-app purchases:** none


### smartDF

[App page](https://appshunter.io/ios/app/smartdf/id1568556062)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is rtl_tcp SDR free?

rtl_tcp SDR costs $12.99, with no in-app purchases.

### Is smartDF free?

smartDF is free to download, with no in-app purchases.

### Do rtl_tcp SDR or smartDF have ads?

Neither rtl_tcp SDR nor smartDF shows ads.

### Which is updated more often, rtl_tcp SDR or smartDF?

rtl_tcp SDR ships an update every 4 months, and smartDF weekly. Most recently, rtl_tcp SDR was updated on October 23, 2026 and smartDF on October 25, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*