# 555 Timer & Oscillators Guide vs Power Electronics

The clearest difference is in-app purchases: 555 Timer & Oscillators Guide at none against Power Electronics's 6. Power Electronics's advantage is ads (none vs shown) and update cadence (every 2 months vs every 5 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Power Electronics sells 6 in-app purchases, starting at $9.99 per month. 555 Timer & Oscillators Guide asks for nothing beyond the download.

555 Timer & Oscillators Guide ships an update every 5 months, Power Electronics every 2 months. The most recent releases landed on September 24, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | 555 Timer & Oscillators Guide | Power Electronics |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/power-electronics/id6737322555/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | — | Free with in-app purchases |
| Size | 24 MB | 22 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | +4 | 4+ |
| Developer | [ALG Software Lab](https://appshunter.io/developer/1650561236) | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) |

## What reviewers say

### 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


### Power Electronics

[App page](https://appshunter.io/ios/app/power-electronics/id6737322555)

This quiz app covers over 70 topics in power electronics, including switches, drive circuits, regulators, and various electronic components. It's designed to help users master the subject through interactive learning.

**Highlights:** Over 70 power electronics topics, Covers switches, drive circuits, regulators, Detailed component listings, Interactive quiz format, Master power electronics concepts

**Features:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Month | $9.99 | per month |
| 6 Months | $19.99 | per 6 months |
| 1 Year | $29.99 | per year |
| 1500 | $0.99 | one-time |
| 3500 | $1.99 | one-time |
| 9000 | $3.99 | one-time |


## Frequently asked questions

### Is 555 Timer & Oscillators Guide free?

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

### Is Power Electronics free?

Power Electronics is free to download, with in-app purchases available.

### Do 555 Timer & Oscillators Guide or Power Electronics have ads?

555 Timer & Oscillators Guide shows ads; Power Electronics does not.

### Which is updated more often, 555 Timer & Oscillators Guide or Power Electronics?

555 Timer & Oscillators Guide ships an update every 5 months, and Power Electronics every 2 months. Most recently, 555 Timer & Oscillators Guide was updated on September 24, 2026 and Power Electronics on September 18, 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.*