# Pressures vs Timer 555 Calculator Pro

The clearest difference is review sentiment: Timer 555 Calculator Pro at 100% against Pressures's 75%. Timer 555 Calculator Pro also leads on update cadence (every 3 months vs every 14 months). Pressures's advantage is rating (5.0 vs 4.7) and iOS requirement (9.0 vs 13.2). On price, ratings volume, ads and in-app purchases there is nothing between them.

Pressures costs $0.99 and Timer 555 Calculator Pro $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Pressures holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 2 and 3 respectively. Written reviews complicate that: 75% of Pressures's written reviews are positive against 100% of Timer 555 Calculator Pro's, so the app with the better star average is not the one people write more warmly about.

Pressures ships an update every 14 months, Timer 555 Calculator Pro every 3 months. The most recent releases landed on October 8, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Pressures | Timer 555 Calculator Pro |
| --- | --- | --- |
| Price | $0.99 | $0.99 |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/pressures/id472040928/reviews)** | [4.7 (3 ratings)](https://appshunter.io/ios/app/timer-555-calculator-pro/id833443125/reviews) |
| Number of ratings | 2 | **3** |
| Positive reviews | 75.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 14 months | **Every 3 months** |
| Monetization | Paid | Paid |
| Size | 21 MB | 3 MB |
| Requires iOS | **9.0** | 13.2 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [LionsApp di Nallbati Elton](https://appshunter.io/developer/432915499) | [Siu Yuen Ho](https://appshunter.io/developer/814088527) |

## What reviewers say

### Pressures

[App page](https://appshunter.io/ios/app/pressures/id472040928)

Easily convert pressure measurements between bar, atm, MPa, and psi. This tool offers automatic conversion as you type and allows you to share your results. Its intuitive design ensures a smooth and pleasant user experience.

**Highlights:** Automatic conversion for bar, atm, psi, MPa, Copy conversion results, Share conversions, Intuitive graphics, Ease of use

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

**In-app purchases:** none


### Timer 555 Calculator Pro

[App page](https://appshunter.io/ios/app/timer-555-calculator-pro/id833443125)

Calculate parameters for monostable and astable circuits. Find component combinations for desired pulse width or frequency. Share circuit files via iCloud Drive or AirDrop.

**Highlights:** Calculate monostable pulse width, Calculate astable frequency, Find component combinations, Adjust component tolerance, Unlimited combinations (Pro), Share circuit files

**In-app purchases:** none


## Frequently asked questions

### Is Pressures free?

Pressures costs $0.99, with no in-app purchases.

### Is Timer 555 Calculator Pro free?

Timer 555 Calculator Pro costs $0.99, with no in-app purchases.

### Which has better reviews, Pressures or Timer 555 Calculator Pro?

Pressures is rated higher. Pressures averages 5.0 out of 5 from 2 ratings, while Timer 555 Calculator Pro averages 4.7 from 3 ratings.

### Do Pressures or Timer 555 Calculator Pro have ads?

Neither Pressures nor Timer 555 Calculator Pro shows ads.

### Which is updated more often, Pressures or Timer 555 Calculator Pro?

Pressures ships an update every 14 months, and Timer 555 Calculator Pro every 3 months. Most recently, Pressures was updated on October 8, 2026 and Timer 555 Calculator Pro on October 5, 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.*