# Units vs Concrete Foundation Calculator

The clearest difference is price: Units at Free against Concrete Foundation Calculator's $6.99. Concrete Foundation Calculator's advantage is in-app purchases (none vs 3) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

Units is free to download; Concrete Foundation Calculator costs $6.99 up front. Units sells 3 one-off in-app purchases. Concrete Foundation Calculator asks for nothing beyond the download.

Units ships an update monthly, Concrete Foundation Calculator daily. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Units | Concrete Foundation Calculator |
| --- | --- | --- |
| Price | **Free** | $6.99 |
| Rating | **[4.1 (51 ratings)](https://appshunter.io/ios/app/units-pro-unit-converter/id284574017/reviews)** | — |
| Number of ratings | **51** | — |
| Positive reviews | 60.1% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Daily** |
| Monetization | Free with in-app purchases | — |
| Size | 86 MB | 35 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Homegrown Software Ltd](https://appshunter.io/developer/406645730) | [Fengbang Yang](https://appshunter.io/developer/1796064748) |

## What reviewers say

### Units

[App page](https://appshunter.io/ios/app/units-pro-unit-converter/id284574017)

Easily convert between hundreds of units across 43 categories, including currency with daily updated rates. Customize your workflow by hiding or reordering units and categories.

**Highlights:** Hundreds of units across 43 categories, Daily updated currency exchange rates, Hide unused units, Reorder units and categories, Universal app support (iPhone, iPod touch, iPad)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $0.99 | one-time |
| Medium Tip | $2.99 | one-time |
| Large Tip | $4.99 | one-time |

**What reviewers like**

- 🚀 Efficient and fast conversions
- 👍 Comprehensive list of units
- 🔍 Customizable unit selection
- 💰 Free app with optional paid version
- 🔧 Useful for engineering and technical work

**What reviewers complain about**

- 🐛 Crashes and stability issues
- 🕰️ Outdated currency conversion rates
- 🔍 Too many unit categories, hard to navigate
- 💰 Ads in free version
- 📏 Ruler feature not accurate on some devices

**Reported bugs**

- Crashes when clearing input fields
- Numerical keypad covers conversion results
- Incompatibility issues with newer iOS versions
- Ruler measurements not accurate on all devices

**Requested features**

- Add nautical units (miles, knots)
- Improve currency conversion accuracy and updates
- Allow customization of visible unit categories
- Add more clothing/shoe size conversions
- Improve user interface and search functionality


### Concrete Foundation Calculator

[App page](https://appshunter.io/ios/app/concrete-foundation-calculator/id6741881021)

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

**In-app purchases:** none


## Frequently asked questions

### Is Units free?

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

### Is Concrete Foundation Calculator free?

Concrete Foundation Calculator costs $6.99, with no in-app purchases.

### Do Units or Concrete Foundation Calculator have ads?

Units shows ads; Concrete Foundation Calculator does not.

### Which is updated more often, Units or Concrete Foundation Calculator?

Units ships an update monthly, and Concrete Foundation Calculator daily. Most recently, Units was updated on November 6, 2026 and Concrete Foundation Calculator on October 30, 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.*