Comparison

Resistor Tools Pro 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 Pro

This utility app offers a suite of tools for calculating and finding resistor combinations. It's designed for electronics enthusiasts and professionals needing to determine series, parallel, and voltage divider configurations. Save and share your calculations easily.

Highlights
  • Calculate series/parallel resistance
  • Find resistor combinations for desired resistance
  • Voltage divider ratio and value calculation
  • Inverting amplifier gain calculation
  • Save combinations to CSV
  • Share via AirDrop
  • Upload CSV to iCloud Drive
Read full description

This app is a collection of resistor calculators. It is suitable for hobbyist or electronic engineer. * Calculate resistance of 2 resistors in series or parallel * Find out combinations of 2 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 * Share document via AirDrop * Upload CSV file to iCloud Drive (For iOS8 or later)

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 Tools Pro4 screens
Operational Amplifiers Guide4 screens

Verdict

The call

The clearest difference is price: Operational Amplifiers Guide at Free against Resistor Tools Pro's $0.99. Resistor Tools Pro's advantage is ads (none vs shown) and iOS requirement (12.0 vs 16.0). On update cadence, 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

Operational Amplifiers Guide is free to download; Resistor Tools Pro costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on June 25, 2026 and September 19, 2026 respectively.

Scorecard3 real differences · 6 level
Resistor Tools Pro versus Operational Amplifiers Guide: the parameters behind the verdict, then further details
ParameterResistor Tools ProOperational Amplifiers Guide
Price$0.99Free — better
Rating4.0 (1 ratings) — better
Number of ratings1 — better
Update frequencyEvery 2 monthsEvery 2 months
AdsNo — betterYes
In-app purchasesNoNo
MonetizationPaid
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

None

Resistor Tools Pro

No in-app purchases

None

Operational Amplifiers Guide

No in-app purchases

Questions

Is Resistor Tools Pro free?
Resistor Tools Pro costs $0.99, with no in-app purchases.
Is Operational Amplifiers Guide free?
Operational Amplifiers Guide is free to download, with no in-app purchases.
Do Resistor Tools Pro or Operational Amplifiers Guide have ads?
Operational Amplifiers Guide shows ads; Resistor Tools Pro does not.
Which is updated more often, Resistor Tools Pro or Operational Amplifiers Guide?
Resistor Tools Pro ships an update every 2 months, and Operational Amplifiers Guide every 2 months. Most recently, Resistor Tools Pro was updated on June 25, 2026 and Operational Amplifiers Guide on September 19, 2026.

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