# Nervous System Flashcards vs Millennium Problems

The clearest difference is price: Millennium Problems at Free against Nervous System Flashcards's $2.99. Millennium Problems also leads on update cadence (every 4 days vs every 22 months). Nervous System Flashcards's advantage is iOS requirement (11.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

Millennium Problems is free to download; Nervous System Flashcards costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Nervous System Flashcards ships an update every 22 months, Millennium Problems every 4 days. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Nervous System Flashcards | Millennium Problems |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/millennium-problems/id6761263693/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 22 months | **Every 4 days** |
| Monetization | — | Free |
| Size | 20 MB | 9 MB |
| Requires iOS | **11.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Hasan Cakir](https://appshunter.io/developer/814343093) | [Loic Fonkam](https://appshunter.io/developer/1884693208) |

## What reviewers say

### Nervous System Flashcards

[App page](https://appshunter.io/ios/app/nervous-system-flashcards/id1415699561)

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

**In-app purchases:** none


### Millennium Problems

[App page](https://appshunter.io/ios/app/millennium-problems/id6761263693)

Explore seven unsolved mathematical mysteries, each with a million-dollar prize. This app adapts content for all skill levels, from middle schoolers to doctoral researchers, with interactive 3D visualizations and built-in quizzes. Learn at your own pace, offline, with no ads or subscriptions.

**Highlights:** Explains seven major unsolved math problems, Content adapts to skill level (Grade 6 to Graduate), Interactive 3D visualizations, Built-in quizzes with XP and badges, Offline functionality, Optional biometric lock

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

**In-app purchases:** none


## Frequently asked questions

### Is Nervous System Flashcards free?

Nervous System Flashcards costs $2.99, with no in-app purchases.

### Is Millennium Problems free?

Millennium Problems is free to download, with no in-app purchases.

### Do Nervous System Flashcards or Millennium Problems have ads?

Neither Nervous System Flashcards nor Millennium Problems shows ads.

### Which is updated more often, Nervous System Flashcards or Millennium Problems?

Nervous System Flashcards ships an update every 22 months, and Millennium Problems every 4 days. Most recently, Nervous System Flashcards was updated on November 3, 2026 and Millennium Problems on November 5, 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.*