Comparison

Math Queen / Math King vs 555 Timer & Oscillators Guide

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Math Queen / Math King

Features
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Math Queen / Math King – Master Mathematics Through Play Learning math has never been more fun! Math Queen and Math King combine mental arithmetic, logic, and concentration in an entertaining puzzle game suitable for all ages. Every game creates a brand-new set of math challenges. Some numbers are missing, and it's your job to drag the correct numbers into the right places. Complete every equation to finish the round successfully. Because the puzzles are generated again and again, every game is different and offers a fresh challenge. Features • Unlimited randomly generated math puzzles • Simple and intuitive drag-and-drop controls • Practice addition, subtraction, multiplication, and division • Improves mental arithmetic and logical thinking • Enhances concentration and memory • Built-in timer to challenge yourself • Error counter to track your progress • Suitable for children, students, and adults • Perfect for learning, school, and daily brain training Whether you want to improve your math skills, keep your mind sharp, or simply enjoy solving clever number puzzles, Math Queen and Math King are the perfect companions. How fast can you solve every puzzle?

About

555 Timer & Oscillators Guide

Features
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Master the design of oscillators and waveform generators using 555 timer integrated circuits, digital logic integrated circuits, operational amplifiers, and transistors. The application provides a comprehensive collection of over 130 tutorials and circuit diagrams, covering 555 timer circuits and practical applications, CMOS 4000 series logic oscillators, TTL 74LS and 74HC series oscillators, operational amplifier–based waveform generators, and transistor multivibrators. Designed for electronics beginners, students, hobbyists, and professional engineers, the app serves as a complete reference and learning tool for designing, understanding, and building oscillators, multivibrators, pulse generators, and waveform circuits commonly used in both analog and digital electronics. In addition to tutorials and schematics, the app includes built-in calculators for frequency, timing, duty cycle, and component value estimation, helping users quickly calculate and adjust circuit parameters. All topics are presented with clear circuit diagrams and detailed explanations. Available in 14 Languages: • English, French, German, Indonesian, Italian, Japanese, Polish, Portuguese, Russian, Simplified Chinese, Spanish, Turkish, Ukrainian, and Vietnamese — study in your native language! Covered Topics: • 555 Timer IC Series • Astable, monostable, and bistable modes • Pulse Width Modulation (PWM) • Voltage conversion circuits • Sensor and external module interfacing • CMOS Logic Oscillators • CMOS 4000 series circuits • Astable, monostable, and bistable modes • Gated CMOS oscillators • TTL / HC Logic Oscillators • TTL 74LS series circuits • 74HC series logic oscillators • Astable and monostable modes • Operational Amplifier Oscillators • Sine wave generators • Square-wave pulse generators • Triangle wave generators • Transistor-Based Oscillators • Transistor-Based Astable multivibrators • Transistor-Based Monostable multivibrators The content is regularly updated and expanded with each new release, ensuring the latest tutorials and circuit examples are always available.

Screenshots

Math Queen / Math King4 screens
555 Timer & Oscillators Guide4 screens

Verdict

The call

The clearest difference is ads: Math Queen / Math King at none against 555 Timer & Oscillators Guide's shown. 555 Timer & Oscillators Guide's advantage is update cadence (every 5 months vs every 30 months) and iOS requirement (16.0 vs 26.0). On price, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

Math Queen / Math King ships an update every 30 months, 555 Timer & Oscillators Guide every 5 months. The most recent releases landed on September 14, 2026 and September 24, 2026 respectively.

Scorecard3 real differences · 3 level
Math Queen / Math King versus 555 Timer & Oscillators Guide: the parameters behind the verdict, then further details
ParameterMath Queen / Math King555 Timer & Oscillators Guide
PriceFreeFree
Update frequencyEvery 30 monthsEvery 5 months — better
AdsNo — betterYes
In-app purchasesNoNo
DevicesiPhone, iPadiPhone, iPad
Requires iOS26.016.0 — better
Further details — not scored
Size11 MB24 MB
Age rating4++4
DeveloperGerhard LentschikALG Software Lab

In-app purchases

None

Math Queen / Math King

No in-app purchases

None

555 Timer & Oscillators Guide

No in-app purchases

Questions

Is Math Queen / Math King free?
Math Queen / Math King is free to download, with no in-app purchases.
Is 555 Timer & Oscillators Guide free?
555 Timer & Oscillators Guide is free to download, with no in-app purchases.
Do Math Queen / Math King or 555 Timer & Oscillators Guide have ads?
555 Timer & Oscillators Guide shows ads; Math Queen / Math King does not.
Which is updated more often, Math Queen / Math King or 555 Timer & Oscillators Guide?
Math Queen / Math King ships an update every 30 months, and 555 Timer & Oscillators Guide every 5 months. Most recently, Math Queen / Math King was updated on September 14, 2026 and 555 Timer & Oscillators Guide on September 24, 2026.

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