# Voltage Regulator vs 555 Timer & Oscillators Guide

The clearest difference is in-app purchases: 555 Timer & Oscillators Guide at none against Voltage Regulator's 1. Voltage Regulator's advantage is ads (none vs shown) and iOS requirement (12.0 vs 16.0). On price, update cadence and device support there is nothing between them.

Both are free to download. Voltage Regulator sells 1 one-off in-app purchase. 555 Timer & Oscillators Guide asks for nothing beyond the download.

Voltage Regulator ships an update every 9 months, 555 Timer & Oscillators Guide every 5 months. The most recent releases landed on September 16, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Voltage Regulator | 555 Timer & Oscillators Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (5 ratings)](https://appshunter.io/ios/app/voltage-regulator/id1149145965/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 9 months | **Every 5 months** |
| Monetization | Freemium | — |
| Size | 3 MB | 24 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | +4 |
| Developer | [Siu Yuen Ho](https://appshunter.io/developer/814088527) | [ALG Software Lab](https://appshunter.io/developer/1650561236) |

## What reviewers say

### Voltage Regulator

[App page](https://appshunter.io/ios/app/voltage-regulator/id1149145965)

Calculate resistor combinations for adjustable voltage regulators. This tool helps electronics hobbyists and professionals determine desired output voltages and resistor values. Results can be exported and shared easily.

**Highlights:** Adjustable voltage regulator support, Calculate resistor combinations, Determine resistor values, Export results to CSV, Share CSV via iCloud/AirDrop

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro features | $1.99 | one-time |


### 555 Timer & Oscillators Guide

[App page](https://appshunter.io/ios/app/555-timer-and-oscillators-guide/id6504487994)

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

**In-app purchases:** none


## Frequently asked questions

### Is Voltage Regulator free?

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

### Is 555 Timer & Oscillators Guide free?

555 Timer & Oscillators Guide is free to download, with no in-app purchases.

### Do Voltage Regulator or 555 Timer & Oscillators Guide have ads?

555 Timer & Oscillators Guide shows ads; Voltage Regulator does not.

### Which is updated more often, Voltage Regulator or 555 Timer & Oscillators Guide?

Voltage Regulator ships an update every 9 months, and 555 Timer & Oscillators Guide every 5 months. Most recently, Voltage Regulator was updated on September 16, 2026 and 555 Timer & Oscillators Guide on September 24, 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.*