Download Android Apps and Games
AppBrain
  • Apps
  • Apps being viewed right now Trending apps today Most popular apps All-time most downloaded apps Top rated apps iPhone and iPad apps
  • Intelligence ▾
    Intelligence overview → Track any Android app or your whole market
    Track & analyze
    Keyword Tracker & OptimizerTrack & improve Play rankings App Performance ReportOne-off PDF for any app StatisticsFree Android & Play market stats
    Promote your app
    Featured Apps App Links
  • Intelligence
  • Pricing
  • Dashboard
  • Sign up
  • Log in
Last updated on: 2026-09-21
Android Apps > Educational > Doomsday Trainer
Doomsday Trainer icon

Doomsday Trainer

6.1.5
Inefficient Code
0.00
0 reviews
500+
Downloads
Free

Calculate the day of the week for any date in history. Train your brain!

Doomsday Trainer Screenshot 1 of 7
Doomsday Trainer Screenshot 2 of 7
Doomsday Trainer Screenshot 3 of 7
Doomsday Trainer Screenshot 4 of 7
Doomsday Trainer Screenshot 5 of 7
Doomsday Trainer Screenshot 6 of 7
Doomsday Trainer Screenshot 7 of 7
Download from Google Play Also on the App Store

About Doomsday Trainer

Doomsday Trainer is an educational app developed by Inefficient Code.

Download Statistics

Doomsday Trainer has been downloaded 930 times. In the last 30 days, the app was downloaded 160 times.

User Ratings

The app has no ratings yet.

App Information

Doomsday Trainer is FREE to download. The APK download size is 13.33 MB. The latest version available is 6.1.5. The last update was on September 13, 2026.

Technical Requirements

The app has a content rating of Everyone. The app has been available on Google Play March 2026.

Description
Can you figure out that March 15, 1937 was a Monday — in under 5 seconds?

Doomsday Trainer — Name Any Day in Your Head teaches you the mental calendar calculation techniques used by competitive memory athletes and calendar savants. Start slow, build the skill, then race the clock.

๐ŸŽฎ THE GAME
Every round, you're shown a random date from across the centuries. Your goal: name the correct day of the week as fast as possible.

• Build Your Streak: Answer correctly and your streak grows. Answer wrong and it's over.
• Beat the Clock: A countdown timer keeps the pressure on, getting tighter the longer your streak runs.

Build the longest streak. Set the fastest average speed. Climb the global rankings.

๐Ÿง  FIVE METHODS TO MASTER
Not everyone thinks the same way. Doomsday Trainer teaches five proven calculation techniques, each with its own step-by-step training mode:

• Doomsday: The classic anchor-date method used by world memory champions.
• Wollin Shortcut: A two-part system using vectorized Doomsday codes and Doomyear sequences for lightning-fast results.
• Odd + 11: An elegant carry-free approach with no multiplication.
• Mod 28: Subtract chunks of 28, count leaps, done.
• Conway: Dozens, remainder, and leaps in one smooth pass.

Training mode walks you through every calculation step-by-step, featuring progressive hints, a full reference Databank, and a built-in Wollin lookup table.

๐ŸŽฏ FOCUSED DRILLS
Isolate the parts that slow you down. Eight targeted drill modes sharpen the individual skills that feed into every calculation:

• Month Anchors
• Century Anchors
• Year Offset
• Modulo 7
• Add / Subtract
• Times Tables
• The Wollin Shortcut
• Leap Year Detection

Track your progress across every drill category with detailed accuracy breakdowns and improvement charts.

โš”๏ธ BATTLE REAL OPPONENTS
Challenge players around the world in real-time 1v1 Best-of-5 matches.

• Fair Competition: Both players receive identical dates (same seed, same sequence), so the result is pure speed and accuracy.
• Ghost Matchmaking: No live opponent online? The game instantly matches you with a ghost recording of a real player from your skill range.
• Rank Up: Earn Elo rating and climb the competitive 1v1 leaderboard.

๐ŸŒ GLOBAL LEADERBOARDS
Compete for the top of two global rankings. Your scores sync automatically so you can see exactly where you stand worldwide.

• Longest Streak: How many correct answers in a row can you get?
• Fastest Speed: What's your best average over 5 consecutive answers?

๐Ÿ“ˆ TRACK YOUR PROGRESS
• Speed and accuracy charts for the past 7 days, 30 days, or full year.
• Personal best streak and speed records.
• Training and drill completion history.
• Full game-by-game breakdown.

โœจ FEATURES
• Multiple visual themes to customize your experience.
• Adjustable font size and layout options.
• Full coverage of edge cases, including leap year handling and century shifts.

Whether you're a memory sports competitor, a maths enthusiast, or just someone who wants a genuinely unusual party trick — Doomsday Trainer will get you there.

Recent changes:
New in v6.1.5: Integrated explanation engine
Show more Show less

More data about Doomsday Trainer

Price Free to download
Total downloads 930
Recent downloads 160
Rating No ratings
Ranking Not ranked
Version 6.1.5
APK size 13.3 MB
Number of libraries ?
Suitable for Everyone
Ads NO ads

App Performance Report

Get a detailed PDF report for Doomsday Trainer with download trends, rating history, and key performance statistics โ€” useful for competitive research or tracking your own app. Learn more

Get PDF Report โ€” $29

Also available on the App Store

Doomsday Trainer icon Doomsday Trainer
Maarten Claessen
5.0
Free
1 ratings

Alternative downloads for the Doomsday Trainer app

Doomsday Clock icon Doomsday Clock
Aethervex
4.1
Free
10,000+
LuckRoll icon LuckRoll
GoodAtSwift, LLC
4.6
Free
1,000+
Time Since icon Time Since
Copur
4.7
Free
10,000+
Streak Tracker - StreakUp icon Streak Tracker - StreakUp
Aura App Studio
4.5
Free
50,000+
Days Calculator icon Days Calculator
Synergie Apps
4.1
Free
500,000+
MyStreaks - Streak Tracker icon MyStreaks - Streak Tracker
Streaking Mastery
3.4
Free
10,000+
Life Engine: Habit Tracker icon Life Engine: Habit Tracker
Kafra Technologies
4.2
Free
5,000+
Mental Math Master Brain Game icon Mental Math Master Brain Game
Aurelien Texier
5.0
Free
100,000+

Doomsday Trainer compared with similar apps

Common keywords of similar apps

Doomsday Speed Trainer Calculation Step Full Year Memory Global Wollin Drill Accuracy Real History Teaches Calendar Techniques Competitive Slow Skill Clock Correct Fast Answer Longest Fastest Average Climb Rankings Mode World Shortcut Subtract Leaps Anchors Century Leap Charts Players Matches Streak Game Day Date Build Training Week Track Progress

Keywords missing from this app

Daily Time Days Streaks Habits App Habit Routine Math Dice Tracker Mental Rewards Work Recent Free Perfect Stay Blocking Word Start Performance Daybloc Life Challenge Focus Deep Calculator Planner Words Games Make Play Improve Brain Win Grow Unlock Features Complete Share

Top rated similar apps (16)

Exatest Arithmetic Speed Drill icon Exatest Arithmetic Speed Drill
SeaGreen Studios
5.0
Free
50,000+
Mathin - Brain Training Game icon Mathin - Brain Training Game
Urban Plugged
5.0
Free
50+
Mental Math Master Brain Game icon Mental Math Master Brain Game
Aurelien Texier
5.0
Free
100,000+
Word Guess icon Word Guess
Vorith Studio
5.0
Free
50+
One Minute Rush icon One Minute Rush
WECS LABS INC
5.0
Free
10,000+
Math Club: Number Puzzle Games icon Math Club: Number Puzzle Games
Evrika Games LLC
4.9
Free
500,000+
Number Games Fast Calculations icon Number Games Fast Calculations
Idea Creative Solutions
4.9
Free
10,000+
Math Games - Brain Challenge icon Math Games - Brain Challenge
Inspector Studios
4.9
Free
10+
Math Tricks Workout & Games icon Math Tricks Workout & Games
JustQuant.com
4.8
Free
1,000,000+
Quick36 Math Challenge icon Quick36 Math Challenge
Quick36
4.8
Free
100,000+
Exactly 10 icon Exactly 10
CollegeFundGames
4.8
Free
100+
Speed Math - Mental Arithmetic icon Speed Math - Mental Arithmetic
Aimtera Labs
4.8
Free
100+
Twisty Timer icon Twisty Timer
Ari Neto
4.8
Free
1,000,000+
Remember the Numbers icon Remember the Numbers
PLAYTOUCH
4.8
Free
10,000+
Mathstronaut - Speed Math icon Mathstronaut - Speed Math
Vaibhav Deshmukh
4.8
Free
5,000+
Math Tricks PRO icon Math Tricks PRO
Mental Math Tricks Academy
4.8
$3.80
10,000+

Most downloaded similar apps (15)

The Almanac icon The Almanac
VOODOO
4.3
Free
1,000,000+
Coin Toss - Win x1000 icon Coin Toss - Win x1000
PlayRoof
4.6
Free
100,000+
Math Tricks: Mental Math icon Math Tricks: Mental Math
Mental Math Tricks Academy
4.5
Free
10,000,000+
Minipuzzles - Daily Challenges icon Minipuzzles - Daily Challenges
Puzztime!
4.5
Free
500,000+
FLIP - Focus Timer for Study icon FLIP - Focus Timer for Study
RinaSoft
4.3
Free
5,000,000+
Days To | Countdown icon Days To | Countdown
miniminiapps
4.7
Free
1,000,000+
Speed Math Mental Quick Games icon Speed Math Mental Quick Games
Standy Software
4.4
Free
5,000,000+
Math Club: Number Puzzle Games icon Math Club: Number Puzzle Games
Evrika Games LLC
4.9
Free
500,000+
Countdown - Days Until icon Countdown - Days Until
Days Until LTD
4.7
Free
1,000,000+
Quick36 Math Challenge icon Quick36 Math Challenge
Quick36
4.8
Free
100,000+
Puzzle Page - Daily Puzzles! icon Puzzle Page - Daily Puzzles!
puzzling.com
4.3
Free
5,000,000+
Countdown Days icon Countdown Days
AppHeaps Team
4.7
Free
500,000+
Countdown - Pretty Progress icon Countdown - Pretty Progress
keinois Oรœ
4.4
Free
100,000+
Step Counter - Pedometer icon Step Counter - Pedometer
Battery Stats Saver
4.5
Free
100,000+
Worde: Daily & Unlimited icon Worde: Daily & Unlimited
ViralMedia-MLM
4.3
Free
500,000+

More from Inefficient Code

Balls on my screen icon Balls on my screen
Inefficient Code
5.0
Free
10,000+
RevEx icon RevEx
Inefficient Code
0.0
Free
500+
Stack Attack icon Stack Attack
Inefficient Code
0.0
Free
500+
Puzzoku icon Puzzoku
Inefficient Code
0.0
Free
500+

Downloads over time

Downloads over time
Subscribe to see download velocity and history

Doomsday Trainer has been downloaded 930 times. Over the past 30 days, it has been downloaded 160 times.

Changelog of Doomsday Trainer

Show changelog

Developer information for Inefficient Code

Inefficient Code

inefficientcode@gmail.com

Legal name:

Address:

Are you the developer of this app? Join us for free to see more information about your app and learn how we can help you promote and earn money with your app.
I'm the developer of this app

Share Doomsday Trainer

Comments on Doomsday Trainer for Android

โ˜…โ˜…โ˜…โ˜…โ˜… Thomas Wollin ยท Mar 27, 2026
Not only does this tool teach you a really cool party trick, it is also an exceptional tool for drilling down basic arithmetic with an intuitive flash card system. My nephew loves the times' table feature up to 20x20! A real hidden gem with a lot of value and a fun challenge.
โ˜…โ˜…โ˜…โ˜…โ˜… Alex Montes ยท Mar 30, 2026
Found on reddit the other day, a few days of light practice later, and I've got it down! 11 in a row is my best streak so far. Super cool math trick and very useful app to practice with. All the updates have been welcome ๐Ÿ‘๐Ÿผ

Google Play Rankings for Doomsday Trainer

This app is not ranked

Technologies used by Doomsday Trainer

9 permissions
Subscribe to see full permission and library details

Frequently asked questions about Doomsday Trainer

Is Doomsday Trainer free?

Yes. Doomsday Trainer is free to download from Google Play.

Is Doomsday Trainer still available?

Yes. Doomsday Trainer is on Google Play, and the last update we saw was on September 13, 2026.

Does Doomsday Trainer contain ads?

No. Google Play does not list Doomsday Trainer as containing ads.

How large is the Doomsday Trainer APK?

The Doomsday Trainer APK is 13.33 MB.

Is Doomsday Trainer suitable for children?

Google Play rates the content of Doomsday Trainer as suitable for everyone.

How many times has Doomsday Trainer been downloaded?

Google Play lists 500+ downloads for Doomsday Trainer.

Who made Doomsday Trainer?

Doomsday Trainer was developed by Inefficient Code. It is listed in the educational category on Google Play.

What are the best alternatives to Doomsday Trainer?

People looking at Doomsday Trainer also look at these educational apps: Doomsday Clock, LuckRoll, Time Since, Streak Tracker - StreakUp, Days Calculator.

Popular Educational Games Today's trending apps Apps on sale Top new apps Apps other people are watching
Overview Reviews Alternatives History Rankings Technology
Doomsday Clock icon Doomsday Clock
LuckRoll icon LuckRoll
Time Since icon Time Since
Streak Tracker - StreakUp icon Streak Tracker - StreakUp
Days Calculator icon Days Calculator
MyStreaks - Streak Tracker icon MyStreaks - Streak Tracker
Life Engine: Habit Tracker icon Life Engine: Habit Tracker
Mental Math Master Brain Game icon Mental Math Master Brain Game
AppBrain Intelligence premium content

Subscribe now to get full and unlimited access to AppBrain Intelligence. You'll have access to:

  • App Intelligence dashboard (performance timeline, competitor comparison, country rankings, insight cards)
  • Detailed ranking data per app
  • Full timeline per developer
  • Device market shares data per country
  • Unlimited keyword tracking
1 Month

$75/mo
(billed every month)

SAVE 0%
Subscribe
3 Months

$65/mo
($195 billed every 3 months)

SAVE 13%
Subscribe
1 Year

$57.50/mo
($690 billed every year)

SAVE 23%
Subscribe
Each subscription will automatically renew 3 days before the expiration date for the same time period. Subscriptions can be cancelled at any time before the renewal.

AppBrain is a directory focused on discovering great apps and games. We give statistics, rankings and search options that Google Play and the App Store don't have. All trademarks are owned by their respective owners. AppBrain doesn't offer APKs or binaries, and always lets users install the official version from Google Play or the App Store.

More apps

  • Top Android apps being viewed
  • Gloomy Tales: Episode 4 f2p stats
  • View NYC ACCESS HRA
  • Time Changer Shortcut

App statistics

  • Android statistics
  • Google Play Developer stats
  • Trending Android Apps
  • Trending iOS apps
  • Top popular Apps
  • Buy the best Android phone

About AppBrain

  • Contact
  • Privacy
  • Documentation
  • DMCA takedowns
  • Articles
  • Blog
  • Top Free Games Apps for your iPhone or iPad
© 2010-2026 - AppBrain