# Timer 555 Calculator vs Pedal Builder

The clearest difference is price: Timer 555 Calculator at Free against Pedal Builder's $1.99. Timer 555 Calculator also leads on update cadence (every 3 months vs every 19 months) and iOS requirement (13.2 vs 16.0). Pedal Builder's advantage is in-app purchases (none vs 1). On ads and device support there is nothing between them.

Timer 555 Calculator is free to download; Pedal Builder costs $1.99 up front. Timer 555 Calculator sells 1 one-off in-app purchase. Pedal Builder asks for nothing beyond the download.

Timer 555 Calculator ships an update every 3 months, Pedal Builder every 19 months. The most recent releases landed on October 5, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Timer 555 Calculator | Pedal Builder |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[3.9 (8 ratings)](https://appshunter.io/ios/app/timer-555-calculator/id834044557/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 19 months |
| Monetization | Free with in-app purchases | — |
| Size | 3 MB | 27 MB |
| Requires iOS | **13.2** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [John Toms](https://appshunter.io/developer/591598841) |

## 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 |


### Pedal Builder

[App page](https://appshunter.io/ios/app/pedal-builder/id6448482080)

**Features:** Vision Pro support

**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 Pedal Builder free?

Pedal Builder costs $1.99, with no in-app purchases.

### Do Timer 555 Calculator or Pedal Builder have ads?

Neither Timer 555 Calculator nor Pedal Builder shows ads.

### Which is updated more often, Timer 555 Calculator or Pedal Builder?

Timer 555 Calculator ships an update every 3 months, and Pedal Builder every 19 months. Most recently, Timer 555 Calculator was updated on October 5, 2026 and Pedal Builder on October 7, 2026.

---

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