# Simple Factors vs Doomsday Method | Mental Game

The clearest difference is rating: Doomsday Method | Mental Game at 4.7 against Simple Factors's 3.8. Doomsday Method | Mental Game also leads on monetization model (free vs paid) and update cadence (monthly vs every 20 months). Simple Factors's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, review sentiment, ratings volume and ads there is nothing between them.

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

Doomsday Method | Mental Game holds the better App Store score, 4.7 against 3.8. Both are backed by a comparable volume of ratings — 5 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Simple Factors ships an update every 20 months, Doomsday Method | Mental Game monthly. The most recent releases landed on October 10, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Simple Factors | Doomsday Method | Mental Game |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.8 (5 ratings)](https://appshunter.io/ios/app/simple-factors/id1084119563/reviews) | **[4.7 (3 ratings)](https://appshunter.io/ios/app/doomsday-method-mental-game/id6447447000/reviews)** |
| Number of ratings | **5** | 3 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 20 months | **Monthly** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 10 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Joseph Palmer](https://appshunter.io/developer/914507761) | [Leon Grimmeisen](https://appshunter.io/developer/1654025400) |

## What reviewers say

### Simple Factors

[App page](https://appshunter.io/ios/app/simple-factors/id1084119563)

This app helps users understand numbers by providing their factors and checking for primality or divisibility. It offers a straightforward interface for quick calculations up to 10 trillion.

**Highlights:** Calculates factors of numbers, Checks for primality, Determines divisibility, Supports numbers up to 10 trillion, Simple, menu-free interface

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

**In-app purchases:** none


### Doomsday Method | Mental Game

[App page](https://appshunter.io/ios/app/doomsday-method-mental-game/id6447447000)

Master the art of calculating weekdays for any date with this comprehensive educational app. Learn a proven technique, practice with interactive exercises, and track your progress to sharpen your mental arithmetic skills.

**Highlights:** Learn Doomsday Method principles, Interactive examples and tips, Dedicated training mode, Progress tracking and statistics, User-friendly interface

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

**In-app purchases:** none


## Frequently asked questions

### Is Simple Factors free?

Simple Factors is free to download, with no in-app purchases.

### Is Doomsday Method | Mental Game free?

Doomsday Method | Mental Game is free to download, with no in-app purchases.

### Which has better reviews, Simple Factors or Doomsday Method | Mental Game?

Doomsday Method | Mental Game is rated higher. Simple Factors averages 3.8 out of 5 from 5 ratings, while Doomsday Method | Mental Game averages 4.7 from 3 ratings.

### Do Simple Factors or Doomsday Method | Mental Game have ads?

Neither Simple Factors nor Doomsday Method | Mental Game shows ads.

### Which is updated more often, Simple Factors or Doomsday Method | Mental Game?

Simple Factors ships an update every 20 months, and Doomsday Method | Mental Game monthly. Most recently, Simple Factors was updated on October 10, 2026 and Doomsday Method | Mental Game on October 14, 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.*