# 555 Calc vs 8051 Tutorial

The clearest difference is rating: 8051 Tutorial at 5.0 against 555 Calc's 4.0. 8051 Tutorial also leads on ads (none vs shown) and update cadence (every 3 months vs every 20 months). 555 Calc's advantage is in-app purchases (none vs 10) and ratings volume (3 vs 1). On price, review sentiment, device support and iOS requirement there is nothing between them.

Both are free to download. 8051 Tutorial sells 10 one-off in-app purchases. 555 Calc asks for nothing beyond the download.

8051 Tutorial holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews split almost evenly too, at 50% and 50% positive.

555 Calc ships an update every 20 months, 8051 Tutorial every 3 months. The most recent releases landed on June 1, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | 555 Calc | 8051 Tutorial |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.0 (3 ratings)](https://appshunter.io/ios/app/555-calc/id868058244/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/8051-tutorial/id1043830861/reviews)** |
| Number of ratings | **3** | 1 |
| Positive reviews | 50.0% of reviews | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 20 months | **Every 3 months** |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 18 MB | 17 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jibiki Works](https://appshunter.io/developer/556845808) | [Siu Yuen Ho](https://appshunter.io/developer/814088527) |

## What reviewers say

### 555 Calc

[App page](https://appshunter.io/ios/app/555-calc/id868058244)

This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.

**Highlights:** Calculate resistor values, Input frequency, Input duty ratio, Input capacitor value, Timer IC 555 circuit design

**Features:** macOS Compatibility

**In-app purchases:** none


### 8051 Tutorial

[App page](https://appshunter.io/ios/app/8051-tutorial/id1043830861)

Learn 8051 microcontroller programming in C with this comprehensive tutorial. It covers architecture, assembly, and C language, featuring 11 practical projects. An optional Pro version offers additional projects with source code and advanced features.

**Highlights:** 8051 architecture review, 8051 assembly mnemonics, 8051 C language programming, 11 practical projects, Baud calculator, Pro version with extra projects and source code

**Features:** Vision Pro support

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 24L01 | $0.99 | one-time |
| 18B20 | $0.99 | one-time |
| OLED | $0.99 | one-time |
| Unlock Pro features | $1.99 | one-time |
| ESP8266 | $1.99 | one-time |
| BMP180 project | $1.99 | one-time |
| DHT11 project | $1.99 | one-time |
| DHT22 project | $1.99 | one-time |
| BMP280 project | $1.99 | one-time |
| Wireless automation (BT) | $1.99 | one-time |


## Frequently asked questions

### Is 555 Calc free?

555 Calc is free to download, with no in-app purchases.

### Is 8051 Tutorial free?

8051 Tutorial is free to download, with in-app purchases available.

### Which has better reviews, 555 Calc or 8051 Tutorial?

8051 Tutorial is rated higher. 555 Calc averages 4.0 out of 5 from 3 ratings, while 8051 Tutorial averages 5.0 from 1 ratings.

### Do 555 Calc or 8051 Tutorial have ads?

555 Calc shows ads; 8051 Tutorial does not.

### Which is updated more often, 555 Calc or 8051 Tutorial?

555 Calc ships an update every 20 months, and 8051 Tutorial every 3 months. Most recently, 555 Calc was updated on June 1, 2026 and 8051 Tutorial on September 16, 2026.

---

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