# Unit Converter Engineering Pro vs Solar Pump

The clearest difference is in-app purchases: Solar Pump at none against Unit Converter Engineering Pro's 2. Unit Converter Engineering Pro's advantage is iOS requirement (13.0 vs 15.1). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Unit Converter Engineering Pro sells 2 in-app purchases, starting at $5.99 per 7 days. Solar Pump asks for nothing beyond the download.

Unit Converter Engineering Pro ships an update weekly, Solar Pump every 4 days. The most recent releases landed on September 15, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | Unit Converter Engineering Pro | Solar Pump |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/unit-converter-engineering-pro/id6757166485/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Weekly | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 77 MB | 25 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kaiguri Tech](https://appshunter.io/developer/1864995084) | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) |

## What reviewers say

### Unit Converter Engineering Pro

[App page](https://appshunter.io/ios/app/unit-converter-engineering-pro/id6757166485)

This app provides precise unit conversions for engineers, scientists, and students. It supports over 100 units across 35 categories, including scientific notation and 9-digit decimal precision. The tool works offline and adheres to SI, NIST, and ISO standards.

**Highlights:** Over 100 units in 35+ categories, Scientific notation support, 9-digit decimal precision, SI, NIST, ISO compliant, Offline functionality, Specialized units included

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 3-Day Trial | $5.99 | per 7 days |
| Yearly Plan | $19.99 | per year |


### Solar Pump

[App page](https://appshunter.io/ios/app/solar-pump-solar-pumping/id6800800302)

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

**In-app purchases:** none


## Frequently asked questions

### Is Unit Converter Engineering Pro free?

Unit Converter Engineering Pro is free to download, with in-app purchases available.

### Is Solar Pump free?

Solar Pump is free to download, with no in-app purchases.

### Do Unit Converter Engineering Pro or Solar Pump have ads?

Neither Unit Converter Engineering Pro nor Solar Pump shows ads.

### Which is updated more often, Unit Converter Engineering Pro or Solar Pump?

Unit Converter Engineering Pro ships an update weekly, and Solar Pump every 4 days. Most recently, Unit Converter Engineering Pro was updated on September 15, 2026 and Solar Pump on September 17, 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.*