# Span vs Model Engine Builder

The clearest difference is ads: Span at none against Model Engine Builder's shown. Span also leads on update cadence (every 5 days vs every 2 weeks). Model Engine Builder's advantage is iOS requirement (15.6 vs 17.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Span sells 1 one-off in-app purchase and Model Engine Builder sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Span ships an update every 5 days, Model Engine Builder every 2 weeks. Both last shipped on October 4, 2026.

## The numbers

| Metric | Span | Model Engine Builder |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 5 days** | Every 2 weeks |
| Size | 60 MB | 20 MB |
| Requires iOS | 17.0 | **15.6** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dodecki Labs](https://appshunter.io/developer/1571436485) | [MIN GYu OH](https://appshunter.io/developer/6803589847) |

## What reviewers say

### Span

[App page](https://appshunter.io/ios/app/span-physics-bridge-builder/id6790187323)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Span Complete | $7.99 | one-time |


### Model Engine Builder

[App page](https://appshunter.io/ios/app/model-engine-builder/id6803801661)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| removeads | $1.99 | one-time |


## Frequently asked questions

### Is Span free?

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

### Is Model Engine Builder free?

Model Engine Builder is free to download, with in-app purchases available.

### Do Span or Model Engine Builder have ads?

Model Engine Builder shows ads; Span does not.

### Which is updated more often, Span or Model Engine Builder?

Span ships an update every 5 days, and Model Engine Builder every 2 weeks. Most recently, Span was updated on October 4, 2026 and Model Engine Builder on October 4, 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.*