# Castillo Digital vs UNOi 4

The clearest difference is review sentiment: UNOi 4 at 50% against Castillo Digital's 13%. UNOi 4 also leads on update cadence (every 6 weeks vs every 5 months). Castillo Digital's advantage is device support (3 vs 1) and iOS requirement (9.0 vs 14.0). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Castillo Digital ships an update every 5 months, UNOi 4 every 6 weeks. The most recent releases landed on October 2, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | Castillo Digital | UNOi 4 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.0 (2 ratings)](https://appshunter.io/ios/app/unoi-4/id1473453935/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 13.0% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 6 weeks** |
| Monetization | Free | Free |
| Size | 18 MB | 135 MB |
| Requires iOS | **9.0** | 14.0 |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | 4+ | 17+ |
| Developer | [Macmillan Administracion Corporativa, S.A. de C.V.](https://appshunter.io/developer/1246458646) | [Grupo Santillana Educacion Global, S.L.](https://appshunter.io/developer/445034184) |

## What reviewers say

### Castillo Digital

[App page](https://appshunter.io/ios/app/castillo-digital/id1249306149)

Access digital textbooks and teacher guides for students. Enhance lessons with interactive activities, videos, and exam generators. Available offline on all devices.

**Highlights:** Digital student books, Teacher guides, Interactive activities, Video resources, Exam generator, Editable planner, Offline access

**Features:** macOS Compatibility

**In-app purchases:** none


### UNOi 4

[App page](https://appshunter.io/ios/app/unoi-4/id1473453935)

This app transforms classroom management by centering the student and breaking down subject barriers. It fosters learning through engagement and practical application, aiming to create transformative citizens.

**Highlights:** Student-centered learning, Interdisciplinary approach, Learning through engagement, Practical application focus, Classroom management transformation

**In-app purchases:** none


## Frequently asked questions

### Is Castillo Digital free?

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

### Is UNOi 4 free?

UNOi 4 is free to download, with no in-app purchases.

### Do Castillo Digital or UNOi 4 have ads?

Neither Castillo Digital nor UNOi 4 shows ads.

### Which is updated more often, Castillo Digital or UNOi 4?

Castillo Digital ships an update every 5 months, and UNOi 4 every 6 weeks. Most recently, Castillo Digital was updated on October 2, 2026 and UNOi 4 on October 16, 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.*