# Doomsday Trainer vs Color Blind Test App

The clearest difference is update cadence: Doomsday Trainer at every 5 days against Color Blind Test App's every 5 weeks. On price, ads, in-app purchases and device support there is nothing between them.

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

Doomsday Trainer ships an update every 5 days, Color Blind Test App every 5 weeks. The most recent releases landed on October 15, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Doomsday Trainer | Color Blind Test App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (2 ratings)](https://appshunter.io/ios/app/doomsday-trainer/id6760719687/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 5 weeks |
| Monetization | Free | — |
| Size | 15 MB | 11 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Maarten Claessen](https://appshunter.io/developer/1885901059) | [Test Apps Limited](https://appshunter.io/developer/1448821868) |

## What reviewers say

### Doomsday Trainer

[App page](https://appshunter.io/ios/app/doomsday-trainer/id6760719687)

Master the Doomsday Algorithm to instantly calculate the day of the week for any historical date. Engage in timed challenges, compete against others, and practice various calculation methods to improve your speed and accuracy.

**Highlights:** Doomsday Algorithm calculation, Timed streak challenges, 1-on-1 live battles, Multiple training methods, Targeted component drills, Step-by-step tutorial

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

**In-app purchases:** none


### Color Blind Test App

[App page](https://appshunter.io/ios/app/color-blind-test-app/id6761285314)

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

**In-app purchases:** none


## Frequently asked questions

### Is Doomsday Trainer free?

Doomsday Trainer is free to download, with no in-app purchases.

### Is Color Blind Test App free?

Color Blind Test App is free to download, with no in-app purchases.

### Do Doomsday Trainer or Color Blind Test App have ads?

Neither Doomsday Trainer nor Color Blind Test App shows ads.

### Which is updated more often, Doomsday Trainer or Color Blind Test App?

Doomsday Trainer ships an update every 5 days, and Color Blind Test App every 5 weeks. Most recently, Doomsday Trainer was updated on October 15, 2026 and Color Blind Test App on October 28, 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.*