# Timer 555 Calculator vs Circuit Simulator Q

The clearest difference is review sentiment: Timer 555 Calculator at 100% against Circuit Simulator Q's 0%. Timer 555 Calculator also leads on rating (3.9 vs 2.7). Circuit Simulator Q's advantage is update cadence (every 2 days vs every 3 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Timer 555 Calculator sells 1 one-off in-app purchase and Circuit Simulator Q sells 2 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Timer 555 Calculator holds the better App Store score, 3.9 against 2.7. Both are backed by a comparable volume of ratings — 8 and 3 respectively. Written reviews point the same way: 100% of Timer 555 Calculator's written reviews are positive against 0% of Circuit Simulator Q's.

Timer 555 Calculator ships an update every 3 months, Circuit Simulator Q every 2 days. The most recent releases landed on September 24, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Timer 555 Calculator | Circuit Simulator Q |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (8 ratings)](https://appshunter.io/ios/app/timer-555-calculator/id834044557/reviews)** | [2.7 (3 ratings)](https://appshunter.io/ios/app/circuit-simulator-q/id6742368702/reviews) |
| Number of ratings | **8** | 3 |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 3 MB | 190 MB |
| Requires iOS | 13.2 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [Ali Mert TUFEKCI](https://appshunter.io/developer/1483311309) |

## 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 Simulator Q

[App page](https://appshunter.io/ios/app/circuit-simulator-q/id6742368702)

Design and simulate complex digital logic circuits with an intuitive interface. Explore basic gates, build counters, ALUs, and even create your own processors. This tool brings your digital electronics ideas to life.

**Highlights:** Advanced circuit design, Qnet netlist algorithm, Build counter circuits and flip-flops, Construct Arithmetic Logic Units (ALUs), Design custom processors

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Plan | $4.99 | per 7 days |
| Yearly Plan | $29.99 | per year |


## Frequently asked questions

### Is Timer 555 Calculator free?

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

### Is Circuit Simulator Q free?

Circuit Simulator Q is free to download, with in-app purchases available.

### Which has better reviews, Timer 555 Calculator or Circuit Simulator Q?

Timer 555 Calculator is rated higher. Timer 555 Calculator averages 3.9 out of 5 from 8 ratings, while Circuit Simulator Q averages 2.7 from 3 ratings.

### Do Timer 555 Calculator or Circuit Simulator Q have ads?

Neither Timer 555 Calculator nor Circuit Simulator Q shows ads.

### Which is updated more often, Timer 555 Calculator or Circuit Simulator Q?

Timer 555 Calculator ships an update every 3 months, and Circuit Simulator Q every 2 days. Most recently, Timer 555 Calculator was updated on September 24, 2026 and Circuit Simulator Q on September 19, 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.*