# 555 Timer & Oscillators Pro vs Circuit Simulator

The clearest difference is price: Circuit Simulator at Free against 555 Timer & Oscillators Pro's $4.99. Circuit Simulator also leads on iOS requirement (15.3 vs 17.0). 555 Timer & Oscillators Pro's advantage is in-app purchases (none vs 8). On update cadence, ads and device support there is nothing between them.

Circuit Simulator is free to download; 555 Timer & Oscillators Pro costs $4.99 up front. Circuit Simulator sells 8 in-app purchases, starting at $0.99 per month. 555 Timer & Oscillators Pro asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 25, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | 555 Timer & Oscillators Pro | Circuit Simulator |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | — | **[4.7 (93 ratings)](https://appshunter.io/ios/app/circuit-simulator-voltsim/id6736870364/reviews)** |
| Number of ratings | — | **93** |
| Positive reviews | — | 76.9% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | — | Free with in-app purchases |
| Size | 22 MB | 105 MB |
| Requires iOS | 17.0 | **15.3** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [ALG Software Lab](https://appshunter.io/developer/1650561236) | [Sindhu Gopi](https://appshunter.io/developer/1773585161) |

## What reviewers say

### 555 Timer & Oscillators Pro

[App page](https://appshunter.io/ios/app/555-timer-and-oscillators-pro/id6504415162)

**Features:** Vision Pro support

**In-app purchases:** none


### Circuit Simulator

[App page](https://appshunter.io/ios/app/circuit-simulator-voltsim/id6736870364)

Design and simulate electronic and digital circuits in real-time. Visualize voltage and current flow, and analyze signals with oscilloscopes and multimeters. Offers a user-friendly experience for circuit design and digital electronic analysis.

**Highlights:** Real-time circuit simulation, Voltage and current analysis, Multichannel oscilloscope, Digital circuit simulation, User-friendly interface, Circuit design tools

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Extensions Subscription | $0.99 | per month |
| Sensors Extension | $0.99 | one-time |
| Custom Chips Extension | $1.99 | one-time |
| Instruments extension | $2.99 | one-time |
| Analog Extension | $3.99 | one-time |
| Misc Extension | $3.99 | one-time |
| Digital Extension | $3.99 | one-time |
| Extension Pack | $12.99 | one-time |


## Frequently asked questions

### Is 555 Timer & Oscillators Pro free?

555 Timer & Oscillators Pro costs $4.99, with no in-app purchases.

### Is Circuit Simulator free?

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

### Do 555 Timer & Oscillators Pro or Circuit Simulator have ads?

Neither 555 Timer & Oscillators Pro nor Circuit Simulator shows ads.

### Which is updated more often, 555 Timer & Oscillators Pro or Circuit Simulator?

555 Timer & Oscillators Pro ships an update every 2 months, and Circuit Simulator every 2 months. Most recently, 555 Timer & Oscillators Pro was updated on October 25, 2026 and Circuit Simulator on October 30, 2026.

---

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