# iSDR vs HamStudy.org

The clearest difference is rating: HamStudy.org at 4.9 against iSDR's 2.5. HamStudy.org also leads on review sentiment (94% vs 52%) and in-app purchases (none vs 1). iSDR's advantage is price ($0.99 vs $3.99) and iOS requirement (9.0 vs 16.4). On ads and device support there is nothing between them.

iSDR costs $0.99 and HamStudy.org $3.99 up front. iSDR sells 1 one-off in-app purchase. HamStudy.org asks for nothing beyond the download.

HamStudy.org holds the better App Store score, 4.9 against 2.5. That said, the two scores are not equally well evidenced: HamStudy.org has 2.6K 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 94% of HamStudy.org's.

iSDR ships an update every 3 months, HamStudy.org every 3 weeks. The most recent releases landed on October 4, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | iSDR | HamStudy.org |
| --- | --- | --- |
| Price | **$0.99** | $3.99 |
| Rating | [2.5 (11 ratings)](https://appshunter.io/ios/app/isdr/id480077371/reviews) | **[4.9 (2.6K ratings)](https://appshunter.io/ios/app/hamstudyorg/id1371288324/reviews)** |
| Number of ratings | 11 | **2.6K** |
| Positive reviews | 51.7% of reviews | **93.7% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Monetization | Paid | **Free** |
| Best chart rank | — | **#5** |
| Size | 36 MB | 30 MB |
| Requires iOS | **9.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Digital Confections LLC](https://appshunter.io/developer/480077374) | [Signal Stuff](https://appshunter.io/developer/1371288323) |

## 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 |


### HamStudy.org

[App page](https://appshunter.io/ios/app/hamstudyorg/id1371288324)

**Currently charting:** #5 Top Paid · Education, #60 Top Paid (US App Store)

This app offers an intelligent study mode that tracks your progress and focuses on areas where you struggle. It allows you to tailor your study to specific chapters and topics from license manuals, with explanations for difficult questions. Practice exams are also available.

**Highlights:** Intelligent study algorithms, Vetted user-submitted explanations, Infinite practice exams, Study all US Amateur Radio question pools, International question pools, Multi-user support, Cross-device progress sync

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Great study tool
- 👍 Easy to use
- 🚀 Efficient way to prepare for exams
- 🚀 Comprehensive coverage of exam material
- 👍 Helpful explanations and hints

**What reviewers complain about**

- 🐛 Occasional app freezes
- 👎 Some explanations could be clearer
- 🔋 Battery drain when using app extensively

**Reported bugs**

- Email support not working
- Occasional freezing or crashing

**Requested features**

- Dark mode option
- Ability to clear test history
- More detailed performance analytics
- Spell out acronyms and define technical terms


## Frequently asked questions

### Is iSDR free?

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

### Is HamStudy.org free?

HamStudy.org costs $3.99, with no in-app purchases.

### Which has better reviews, iSDR or HamStudy.org?

HamStudy.org is rated higher. iSDR averages 2.5 out of 5 from 11 ratings, while HamStudy.org averages 4.9 from 2.6K ratings.

### Do iSDR or HamStudy.org have ads?

Neither iSDR nor HamStudy.org shows ads.

### Which is updated more often, iSDR or HamStudy.org?

iSDR ships an update every 3 months, and HamStudy.org every 3 weeks. Most recently, iSDR was updated on October 4, 2026 and HamStudy.org on October 12, 2026.

---

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