# Resistor vs Operational Amplifiers Guide

The clearest difference is ads: Resistor at none against Operational Amplifiers Guide's shown. Operational Amplifiers Guide's advantage is update cadence (every 2 months vs every 9 months) and iOS requirement (16.0 vs 26.0). On price, in-app purchases and device support there is nothing between them.

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

Resistor ships an update every 9 months, Operational Amplifiers Guide every 2 months. The most recent releases landed on September 27, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Resistor | Operational Amplifiers Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (17 ratings)](https://appshunter.io/ios/app/resistor-converter/id6446839759/reviews)** | — |
| Number of ratings | **17** | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 9 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 8 MB | 17 MB |
| Requires iOS | 26.0 | **16.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Gerhard Lentschik](https://appshunter.io/developer/629988041) | [ALG Software Lab](https://appshunter.io/developer/1650561236) |

## What reviewers say

### Resistor

[App page](https://appshunter.io/ios/app/resistor-converter/id6446839759)

Quickly calculate resistor values from color bands or SMD codes, and vice versa. This tool is ideal for electronics enthusiasts, students, and DIYers working with 4, 5, or 6-band resistors and various SMD codes. It functions offline and requires no registration.

**Highlights:** Calculate resistor values from color bands, Convert resistor values to color bands, Supports 4, 5, and 6-band resistors, Handles SMD codes (EIA-3, EIA-4, EIA-96), Works offline, No registration required

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Operational Amplifiers Guide

[App page](https://appshunter.io/ios/app/operational-amplifiers-guide/id6467499897)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Resistor free?

Resistor is free to download, with no in-app purchases.

### Is Operational Amplifiers Guide free?

Operational Amplifiers Guide is free to download, with no in-app purchases.

### Do Resistor or Operational Amplifiers Guide have ads?

Operational Amplifiers Guide shows ads; Resistor does not.

### Which is updated more often, Resistor or Operational Amplifiers Guide?

Resistor ships an update every 9 months, and Operational Amplifiers Guide every 2 months. Most recently, Resistor was updated on September 27, 2026 and Operational Amplifiers Guide on October 1, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*