Comparison

Resistor Tools vs Operational Amplifiers Guide

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

Head to head
About

Resistor Tools

This utility app provides a suite of tools for calculating and determining resistor values. It assists hobbyists and engineers with series, parallel, and voltage divider calculations, as well as inverting amplifier gain.

Highlights
  • Series and parallel resistor calculation
  • Resistor combination finder
  • Voltage divider ratio and value calculation
  • Inverting amplifier gain calculation
  • Save combinations to CSV
Features
Read full description

This app is a collection of resistor calculators. It is suitable for hobbyist or electronic engineer. * Calculate resistance of two resistors in series or parallel * Find out combinations of two resistors in series/parallel making a desired resistance * Calculate ratio of R1/R2 and voltage divider * Find out resistor values of making voltage divider ratio * Find out resistor values of making inverting amplifier gain * Save combination values in CSV file

About

Operational Amplifiers Guide

Features
Read full description

Operational Amplifiers Guide is your essential tool for designing and analyzing circuits using op-amps and comparators. Whether you're a student, electronics enthusiast, or experienced engineer, this app helps you create, calculate, and understand a wide variety of op-amp–based circuits with ease. Use it as a practical reference when developing projects, building prototypes, or studying amplifier configurations. The app also includes technical data on popular operational amplifier and comparator series — making it a handy guide for both design and selection. 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! Key Features: • Interactive calculators for common op-amp circuits • Step-by-step explanations and formulas • Reference info on op-amps and comparators • Ideal for learning, prototyping, or quick checks • Light and dark mode support The application contains the following guides and calculators: Amplifiers • Non-inverting operational amplifier • Inverting operational amplifier • Inverting amplifier with T-bridge in OS • Differential amplifier • Differential amplifier with T-bridge in OS • Voltage repeater • Inverting voltage repeater • AC voltage amplifier • High Input Impedance AC Voltage Amplifier • AC voltage repeater ActiveFilters • Non-inverting low-pass filter • Inverting low-pass filter • Non-inverting high-pass filter • Inverting high pass filter • Bandpass filter • Gyrator Integrators and differentiators • Voltage integrator • Sum integrator • Integrator with signal amplification • Difference integrator • Double integrator • Voltage differentiator • Sum Differentiator • Differentiator with T-bridge • Differentiator with T-bridge made of capacitors • Difference differentiator Comparators • Comparator • Limiter • Limiter with zener diode at the input • RS trigger Attenuators • Non-inverting attenuator • Inverting attenuator Converters • Voltage-to-current converter with non-inverting input • Voltage to current converter with inverting input • Voltage to current converter with differential input Adders and substactors • Inverting adder • Addition-subtraction circuit • Non-inverting adder Logarithmic and exponential amplifiers • Diode-based logarithmic amplifier • Transistor-based logarithmic amplifier • Diode exponential amplifier • Exponential transistor amplifier Sine Wave generators: • Op-Amp Oscillators • Oscillator with Diode in the Feedback Path • Twin-T Network Signal Generator Square-wave pulse generators • Op-Amp Square-Wave Generator • Adjustable Square-Wave Generator • Enhanced Square-Wave Generator • Duty-Cycle Adjustment Triangle-wave signal generators • Nonlinear Triangle-Wave Generator • Variable-Symmetry Sawtooth Generator • Linear Triangle-Wave Generator • Adjustable Linear Triangle-Wave Generator • Variable-Symmetry Ramp Generator Popular operational amplifiers: description and pinout Popular comparators: description and pinout Download now and power up your electronics work!

Screenshots

Resistor Tools4 screens
Operational Amplifiers Guide4 screens

Verdict

The call

The clearest difference is in-app purchases: Operational Amplifiers Guide at none against Resistor Tools's 1. Resistor Tools's advantage is ads (none vs shown) and iOS requirement (12.0 vs 16.0). On price, update cadence 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. Resistor Tools sells 1 one-off in-app purchase. Operational Amplifiers Guide asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 26, 2026 and September 19, 2026 respectively.

Scorecard3 real differences · 7 level
Resistor Tools versus Operational Amplifiers Guide: the parameters behind the verdict, then further details
ParameterResistor ToolsOperational Amplifiers Guide
PriceFreeFree
Rating5.0 (10 ratings) — better—
Positive reviews75.0% of reviews—
Number of ratings10 — better—
Update frequencyEvery 2 monthsEvery 2 months
AdsNo — betterYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS12.0 — better16.0
Further details — not scored
Size4 MB17 MB
Age rating4+4+
DeveloperSiu Yuen HoALG Software Lab

In-app purchases

1 purchases

Resistor Tools

One-time1
  • Unlock pro feature$0.99
None

Operational Amplifiers Guide

No in-app purchases

Questions

Is Resistor Tools free?
Resistor Tools is free to download, with in-app purchases available.
Is Operational Amplifiers Guide free?
Operational Amplifiers Guide is free to download, with no in-app purchases.
Do Resistor Tools or Operational Amplifiers Guide have ads?
Operational Amplifiers Guide shows ads; Resistor Tools does not.
Which is updated more often, Resistor Tools or Operational Amplifiers Guide?
Resistor Tools ships an update every 2 months, and Operational Amplifiers Guide every 2 months. Most recently, Resistor Tools was updated on September 26, 2026 and Operational Amplifiers Guide on September 19, 2026.

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