# HSF Study vs Retain

The clearest difference is review sentiment: Retain at 89% against HSF Study's 27%. Retain also leads on ads (none vs shown). HSF Study's advantage is in-app purchases (none vs 2). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Retain sells 2 in-app purchases, starting at $4.99 per month. HSF Study asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 17, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | HSF Study | Retain |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/retain-ai-flashcards/id6469217518/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | 27.3% of reviews | **88.9% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | **Ad-supported** | Freemium |
| Size | 46 MB | 54 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Carl Remigius Fresenius Education AG](https://appshunter.io/developer/681675742) | [Paul Evans](https://appshunter.io/developer/1711681032) |

## What reviewers say

### HSF Study

[App page](https://appshunter.io/ios/app/hsf-study/id1660449017)

Discover suitable Bachelor's or Master's programs with a quiz. Get personalized advice from study counselors and easily apply by scanning your certificates. Manage study documents, access portals, and view your schedule.

**Highlights:** Program finder quiz, Study counseling contact, Certificate scanning for application, Centralized document storage, Bundled portal access, Personalized daily feed, Integrated timetable

**Features:** Vision Pro support

**In-app purchases:** none


### Retain

[App page](https://appshunter.io/ios/app/retain-ai-flashcards/id6469217518)

This minimalist flashcard app uses AI to help you create and study. Its intelligent spaced repetition algorithm optimizes review intervals for efficient learning and rapid progress. Choose from different card layouts to keep your study sessions engaging.

**Highlights:** AI-generated flashcards, Customizable card layouts, Spaced repetition algorithm, Minimalist design, Progress tracking

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $4.99 | per month |
| Premium Yearly | $29.99 | per year |


## Frequently asked questions

### Is HSF Study free?

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

### Is Retain free?

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

### Do HSF Study or Retain have ads?

HSF Study shows ads; Retain does not.

### Which is updated more often, HSF Study or Retain?

HSF Study ships an update every 3 weeks, and Retain every 3 weeks. Most recently, HSF Study was updated on October 17, 2026 and Retain on October 6, 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.*