# Prehab 121 vs Ostello

The clearest difference is in-app purchases: Prehab 121 at none against Ostello's 5. Prehab 121 also leads on iOS requirement (15.1 vs 17.6). Ostello's advantage is update cadence (every 4 days vs every 2 months). On price, ads and device support there is nothing between them.

Both are free to download. Ostello sells 5 one-off in-app purchases. Prehab 121 asks for nothing beyond the download.

Prehab 121 ships an update every 2 months, Ostello every 4 days. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Prehab 121 | Ostello |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/ostello/id6451157739/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | — | Free with in-app purchases |
| Size | 100 MB | 176 MB |
| Requires iOS | **15.1** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Shaunak Chafekar](https://appshunter.io/developer/1571968941) | [Ostello AI](https://appshunter.io/developer/1695110073) |

## What reviewers say

### Prehab 121

[App page](https://appshunter.io/ios/app/prehab-121/id6446013286)

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

**In-app purchases:** none


### Ostello

[App page](https://appshunter.io/ios/app/ostello/id6451157739)

This app offers goal-oriented learning for competitive entrance exams with short videos, expert content, and admission assistance. It provides exam-specific courses, personalized learning paths, and progress tracking to help students build knowledge and confidence.

**Highlights:** Exam-specific courses, Personalized learning paths, Expert-led lessons, Admission assistance, Progress tracking, Mock tests and quizzes

**Features:** Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Live Session Slot | $2.99 | one-time |
| Live Session Plan | $9.99 | one-time |
| Confidence Plus | $39.99 | one-time |
| Fluency Pro | $59.99 | one-time |
| Confidence Pro | $79.99 | one-time |


## Frequently asked questions

### Is Prehab 121 free?

Prehab 121 is free to download, with no in-app purchases.

### Is Ostello free?

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

### Do Prehab 121 or Ostello have ads?

Neither Prehab 121 nor Ostello shows ads.

### Which is updated more often, Prehab 121 or Ostello?

Prehab 121 ships an update every 2 months, and Ostello every 4 days. Most recently, Prehab 121 was updated on October 25, 2026 and Ostello on October 24, 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.*