# FS Nucleus vs Integrity World

The clearest difference is in-app purchases: FS Nucleus at none against Integrity World's 1. FS Nucleus also leads on device support (3 vs 1). Integrity World's advantage is update cadence (every 2 months vs every 9 months). On price, ads and iOS requirement there is nothing between them.

Both are free to download. Integrity World sells 1 one-off in-app purchase. FS Nucleus asks for nothing beyond the download.

FS Nucleus ships an update every 9 months, Integrity World every 2 months. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | FS Nucleus | Integrity World |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 2 months** |
| Size | 33 MB | 85 MB |
| Requires iOS | **15.6** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [FOUNTAINHEAD EDUCATION LLP](https://appshunter.io/developer/1408999214) | [TagMango Inc](https://appshunter.io/developer/1611765353) |

## What reviewers say

### FS Nucleus

[App page](https://appshunter.io/ios/app/fs-nucleus/id1625806958)

**Features:** macOS Compatibility

**In-app purchases:** none


### Integrity World

[App page](https://appshunter.io/ios/app/integrity-world/id6749300535)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Silver Membership | $59.99 | one-time |


## Frequently asked questions

### Is FS Nucleus free?

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

### Is Integrity World free?

Integrity World is free to download, with in-app purchases available.

### Do FS Nucleus or Integrity World have ads?

Neither FS Nucleus nor Integrity World shows ads.

### Which is updated more often, FS Nucleus or Integrity World?

FS Nucleus ships an update every 9 months, and Integrity World every 2 months. Most recently, FS Nucleus was updated on October 27, 2026 and Integrity World on October 24, 2026.

---

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