# iSDR vs ISS Detector

The clearest difference is price: ISS Detector at Free against iSDR's $0.99. ISS Detector also leads on rating (4.6 vs 2.5) and ratings volume (633 vs 11). iSDR's advantage is ads (none vs shown) and iOS requirement (9.0 vs 16.0). On review sentiment, in-app purchases and device support there is nothing between them.

ISS Detector is free to download; iSDR costs $0.99 up front. iSDR sells 1 one-off in-app purchase and ISS Detector sells 11 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

ISS Detector holds the better App Store score, 4.6 against 2.5. That said, the two scores are not equally well evidenced: ISS Detector has 633 ratings behind it against 11, so its average is the more settled of the two. Written reviews point the same way: 52% of iSDR's written reviews are positive against 55% of ISS Detector's.

iSDR ships an update every 3 months, ISS Detector monthly. The most recent releases landed on October 4, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | iSDR | ISS Detector |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [2.5 (11 ratings)](https://appshunter.io/ios/app/isdr/id480077371/reviews) | **[4.6 (633 ratings)](https://appshunter.io/ios/app/iss-detector/id1198597805/reviews)** |
| Number of ratings | 11 | **633** |
| Positive reviews | 51.7% of reviews | **55.1% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 36 MB | 33 MB |
| Requires iOS | **9.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Digital Confections LLC](https://appshunter.io/developer/480077374) | [Derk Vrijdag](https://appshunter.io/developer/1198597804) |

## What reviewers say

### iSDR

[App page](https://appshunter.io/ios/app/isdr/id480077371)

This app allows experimenters and amateur radio enthusiasts to build a portable software-defined radio receiver using their iOS device. It processes radio signals using the device's processor and offers various display and filtering modes. Additional hardware is required for live signal reception.

**Highlights:** Six receive mode settings (USB, LSB, CW, AM, FM, Binaural), Selectable bandwidth settings, 120 dB dynamic range signal strength meter, Three AGC settings (fast, slow, off), Spectrum, Waterfall, and Oscilloscope display modes, Supports downloaded audio-format spectrum files via iTunes, Embed center frequency in file names for automatic display

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Wi-Fi Radio Control | Free | one-time |


### ISS Detector

[App page](https://appshunter.io/ios/app/iss-detector/id1198597805)

Easily track the International Space Station and other satellites. Receive timely alarms before passes and get weather condition checks for optimal viewing. Enhance functionality with optional in-app purchases to discover more celestial objects.

**Highlights:** ISS tracking and alerts, Weather condition checks, Alarm notifications, Track Starlink trains, Track Hubble telescope, Track amateur radio satellites

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (11)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Access | $0.99 | per month |
| Donation | $1.99 | per month |
| Premium Access | $1.99 | per month |
| Premium Access | $2.99 | per year |
| Premium Access | $5.99 | per year |
| Donation | $5.99 | per year |
| Premium Access | $11.99 | per year |
| Starlink and Famous objects | $3.99 | one-time |
| Amateur Radio Satellites | $3.99 | one-time |
| Comets and Planets | $3.99 | one-time |
| Combo package | $5.99 | one-time |


## Frequently asked questions

### Is iSDR free?

iSDR costs $0.99, and also offers in-app purchases.

### Is ISS Detector free?

ISS Detector is free to download, with in-app purchases available.

### Which has better reviews, iSDR or ISS Detector?

ISS Detector is rated higher. iSDR averages 2.5 out of 5 from 11 ratings, while ISS Detector averages 4.6 from 633 ratings.

### Do iSDR or ISS Detector have ads?

ISS Detector shows ads; iSDR does not.

### Which is updated more often, iSDR or ISS Detector?

iSDR ships an update every 3 months, and ISS Detector monthly. Most recently, iSDR was updated on October 4, 2026 and ISS Detector on October 15, 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.*