# Rad Index vs Spintuition

The clearest difference is in-app purchases: Spintuition at none against Rad Index's 1. Spintuition also leads on update cadence (every 4 days vs fortnightly). Rad Index's advantage is iOS requirement (15.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Rad Index sells 1 one-off in-app purchase. Spintuition asks for nothing beyond the download.

Rad Index ships an update fortnightly, Spintuition every 4 days. The most recent releases landed on October 31, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | Rad Index | Spintuition |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.5 (2 ratings)](https://appshunter.io/ios/app/spintuition/id6813756211/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 4 days** |
| Monetization | — | Free |
| Size | 39 MB | 5 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Simone Zen](https://appshunter.io/developer/1896760438) | [BRIAN ANDREW HARGREAVES](https://appshunter.io/developer/6813756693) |

## What reviewers say

### Rad Index

[App page](https://appshunter.io/ios/app/rad-index/id6770671896)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Rad Index Premium | $8.99 | one-time |


### Spintuition

[App page](https://appshunter.io/ios/app/spintuition/id6813756211)

Explore interactive 3D visualizations of MRI spin dynamics for educational purposes. Control RF/gradients and spin behavior, view waveforms, and load pulseq sequences. Ideal for learning and teaching MRI principles.

**Highlights:** Interactive 3D MRI spin dynamics, Control RF/gradients, Direct spin dynamics control, Waveform viewing, Pulseq sequence loading and export, Guided tours and examples

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

**In-app purchases:** none


## Frequently asked questions

### Is Rad Index free?

Rad Index is free to download, with in-app purchases available.

### Is Spintuition free?

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

### Do Rad Index or Spintuition have ads?

Neither Rad Index nor Spintuition shows ads.

### Which is updated more often, Rad Index or Spintuition?

Rad Index ships an update fortnightly, and Spintuition every 4 days. Most recently, Rad Index was updated on October 31, 2026 and Spintuition on October 26, 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.*