# Resistor Tools Pro vs PassNote

The clearest difference is price: PassNote at Free against Resistor Tools Pro's $0.99. Resistor Tools Pro's advantage is in-app purchases (none vs 1) and iOS requirement (12.0 vs 15.6). On update cadence, ads and device support there is nothing between them.

PassNote is free to download; Resistor Tools Pro costs $0.99 up front. PassNote sells 1 one-off in-app purchase. Resistor Tools Pro asks for nothing beyond the download.

Resistor Tools Pro ships an update every 2 months, PassNote every 4 months. The most recent releases landed on June 25, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Resistor Tools Pro | PassNote |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/resistor-tools-pro/id825620924/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 4 months |
| Monetization | Paid | — |
| Size | 4 MB | 83 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [Thanh Nguyen Van](https://appshunter.io/developer/1739986786) |

## What reviewers say

### Resistor Tools Pro

[App page](https://appshunter.io/ios/app/resistor-tools-pro/id825620924)

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

**In-app purchases:** none


### PassNote

[App page](https://appshunter.io/ios/app/passnote-password-vault/id6759524542)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade to Premium | $9.99 | one-time |


## Frequently asked questions

### Is Resistor Tools Pro free?

Resistor Tools Pro costs $0.99, with no in-app purchases.

### Is PassNote free?

PassNote is free to download, with in-app purchases available.

### Do Resistor Tools Pro or PassNote have ads?

Neither Resistor Tools Pro nor PassNote shows ads.

### Which is updated more often, Resistor Tools Pro or PassNote?

Resistor Tools Pro ships an update every 2 months, and PassNote every 4 months. Most recently, Resistor Tools Pro was updated on June 25, 2026 and PassNote on September 8, 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.*