Comparison

Opamp tools vs 555 Timer & Oscillators Guide

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

Head to head
About

Opamp tools

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This app is the collection of operational amplifier calculators. It is suitable for hobbyist or electronic engineer. Features * Inverting amplifier * Non-Inverting amplifier * Differential amplifier * Summing amplifier * Inverting comparator * First-order filter * Second-order filter (HPF) * Phase shift oscillator * Colpitts oscillator * Limit 5 combinations of component values * Share CSV via AirDrop * Upload CSV to iCloud Drive (For iOS8 or later) Pro Features * Instrumentation amplifier * Non-inverting comparator * Second-order filter (LPF) * Wien bridege oscillator * Hartley oscillator * No limitation of the number of suggestions * Selectable 1%,5%,10%,20% of values

About

555 Timer & Oscillators Guide

Features
Read full description

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: β€’ English, French, German, Indonesian, Italian, Japanese, Polish, Portuguese, Russian, Simplified Chinese, Spanish, Turkish, Ukrainian, and Vietnamese β€” study in your native language! Covered Topics: β€’ 555 Timer IC Series β€’ Astable, monostable, and bistable modes β€’ Pulse Width Modulation (PWM) β€’ Voltage conversion circuits β€’ Sensor and external module interfacing β€’ CMOS Logic Oscillators β€’ CMOS 4000 series circuits β€’ Astable, monostable, and bistable modes β€’ Gated CMOS oscillators β€’ TTL / HC Logic Oscillators β€’ TTL 74LS series circuits β€’ 74HC series logic oscillators β€’ Astable and monostable modes β€’ Operational Amplifier Oscillators β€’ Sine wave generators β€’ Square-wave pulse generators β€’ Triangle wave generators β€’ Transistor-Based Oscillators β€’ Transistor-Based Astable multivibrators β€’ 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

Opamp tools4 screens
555 Timer & Oscillators Guide4 screens

Verdict

The call

The clearest difference is in-app purchases: 555 Timer & Oscillators Guide at none against Opamp tools's 1. 555 Timer & Oscillators Guide also leads on update cadence (every 5 months vs every 12 months). Opamp tools's advantage is ads (none vs shown) and iOS requirement (12.0 vs 16.0). On price and device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. Opamp tools sells 1 one-off in-app purchase. 555 Timer & Oscillators Guide asks for nothing beyond the download.

UpkeepUpdate frequency

Opamp tools ships an update every 12 months, 555 Timer & Oscillators Guide every 5 months. The most recent releases landed on May 16, 2026 and September 24, 2026 respectively.

Scorecard4 real differences Β· 2 level
Opamp tools versus 555 Timer & Oscillators Guide: the parameters behind the verdict, then further details
ParameterOpamp tools555 Timer & Oscillators Guide
PriceFreeFree
Update frequencyEvery 12 monthsEvery 5 months β€” better
AdsNo β€” betterYes
In-app purchasesYesNo β€” better
DevicesiPhone, iPad, iPod β€” betteriPhone, iPad
Requires iOS12.0 β€” better16.0
Further details β€” not scored
Size4 MB24 MB
Age rating4++4
DeveloperSiu Yuen HoALG Software Lab

In-app purchases

1 purchases

Opamp tools

One-time1
  • Unlock pro feature$1.99
None

555 Timer & Oscillators Guide

No in-app purchases

Questions

Is Opamp tools free?
Opamp tools is free to download, with in-app purchases available.
Is 555 Timer & Oscillators Guide free?
555 Timer & Oscillators Guide is free to download, with no in-app purchases.
Do Opamp tools or 555 Timer & Oscillators Guide have ads?
555 Timer & Oscillators Guide shows ads; Opamp tools does not.
Which is updated more often, Opamp tools or 555 Timer & Oscillators Guide?
Opamp tools ships an update every 12 months, and 555 Timer & Oscillators Guide every 5 months. Most recently, Opamp tools was updated on May 16, 2026 and 555 Timer & Oscillators Guide on September 24, 2026.

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