# The mark experiment vs FlashStacks

The clearest difference is in-app purchases: The mark experiment at none against FlashStacks's 2. The mark experiment also leads on device support (3 vs 1) and iOS requirement (9.2 vs 17.6). FlashStacks's advantage is update cadence (every 5 days vs every 31 months). On price and ads there is nothing between them.

Both are free to download. FlashStacks sells 2 in-app purchases, starting at $4.99 per month. The mark experiment asks for nothing beyond the download.

The mark experiment ships an update every 31 months, FlashStacks every 5 days. The most recent releases landed on September 8, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | The mark experiment | FlashStacks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.5 (6 ratings)](https://appshunter.io/ios/app/flashstacks-flashcard-study/id6762071988/reviews)** |
| Number of ratings | — | **6** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 31 months | **Every 5 days** |
| Monetization | — | Freemium |
| Size | 14 MB | 10 MB |
| Requires iOS | **9.2** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Jonas Kellert](https://appshunter.io/developer/1187446918) | [Bailey Skewes](https://appshunter.io/developer/1892771018) |

## What reviewers say

### The mark experiment

[App page](https://appshunter.io/ios/app/the-mark-experiment/id1187446919)

**Features:** macOS Compatibility

**In-app purchases:** none


### FlashStacks

[App page](https://appshunter.io/ios/app/flashstacks-flashcard-study/id6762071988)

Transform study materials into interactive Home Screen widgets. AI generates flashcards from PDFs, and spaced repetition optimizes learning. Visualize concepts with image occlusion and track progress with detailed stats.

**Highlights:** Home and Lock Screen widgets, AI-powered PDF to flashcard generation, Spaced repetition learning, Image occlusion cards, Progress tracking and stats, Customizable widget themes

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FlashStacks Premium — Monthly | $4.99 | per month |
| FlashStacks Premium — Annual | $34.99 | per year |


## Frequently asked questions

### Is The mark experiment free?

The mark experiment is free to download, with no in-app purchases.

### Is FlashStacks free?

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

### Do The mark experiment or FlashStacks have ads?

Neither The mark experiment nor FlashStacks shows ads.

### Which is updated more often, The mark experiment or FlashStacks?

The mark experiment ships an update every 31 months, and FlashStacks every 5 days. Most recently, The mark experiment was updated on September 8, 2026 and FlashStacks on September 9, 2026.

---

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