# Timer 555 Calculator vs Circuit Resistance Creator

The clearest difference is rating: Circuit Resistance Creator at 5.0 against Timer 555 Calculator's 3.9. Circuit Resistance Creator also leads on in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 3 months). On price, review sentiment, ratings volume and ads there is nothing between them.

Both are free to download. Timer 555 Calculator sells 1 one-off in-app purchase. Circuit Resistance Creator asks for nothing beyond the download.

Circuit Resistance Creator holds the better App Store score, 5.0 against 3.9. Both are backed by a comparable volume of ratings — 8 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Timer 555 Calculator ships an update every 3 months, Circuit Resistance Creator every 3 weeks. The most recent releases landed on October 21, 2026 and September 26, 2026 respectively.

## The numbers

| Metric | Timer 555 Calculator | Circuit Resistance Creator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (8 ratings)](https://appshunter.io/ios/app/timer-555-calculator/id834044557/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/circuit-resistance-creator/id1475404949/reviews)** |
| Number of ratings | **8** | 3 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 3 MB | 15 MB |
| Requires iOS | **13.2** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [David White](https://appshunter.io/developer/911163945) |

## What reviewers say

### Timer 555 Calculator

[App page](https://appshunter.io/ios/app/timer-555-calculator/id834044557)

Calculate monostable and astable circuits for electronics projects. Determine pulse width and frequency, find component combinations, and save/upload data. Supports multiple languages.

**Highlights:** Monostable circuit pulse width calculation, Astable circuit frequency calculation, Component combination finder, Save component values to CSV, Upload CSV via AirDrop/iCloud Drive, Multi-language support

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro feature | $0.99 | one-time |


### Circuit Resistance Creator

[App page](https://appshunter.io/ios/app/circuit-resistance-creator/id1475404949)

Calculate equivalent resistance for any resistor circuit. This tool is designed for students, technicians, and engineers, offering high accuracy for voltage, current, and resistance. It's a great way to check homework and perform engineering calculations.

**Highlights:** Equivalent resistance calculation, Supports any resistor circuit, High accuracy displays (6 decimal places), Apply custom circuit voltages, Designed for students and engineers, Homework checking tool

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Timer 555 Calculator free?

Timer 555 Calculator is free to download, with in-app purchases available.

### Is Circuit Resistance Creator free?

Circuit Resistance Creator is free to download, with no in-app purchases.

### Which has better reviews, Timer 555 Calculator or Circuit Resistance Creator?

Circuit Resistance Creator is rated higher. Timer 555 Calculator averages 3.9 out of 5 from 8 ratings, while Circuit Resistance Creator averages 5.0 from 3 ratings.

### Do Timer 555 Calculator or Circuit Resistance Creator have ads?

Neither Timer 555 Calculator nor Circuit Resistance Creator shows ads.

### Which is updated more often, Timer 555 Calculator or Circuit Resistance Creator?

Timer 555 Calculator ships an update every 3 months, and Circuit Resistance Creator every 3 weeks. Most recently, Timer 555 Calculator was updated on October 21, 2026 and Circuit Resistance Creator on September 26, 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.*