# coolAltitude vs Simple Ruler inch/cm

The clearest difference is review sentiment: Simple Ruler inch/cm at 100% against coolAltitude's 60%. Simple Ruler inch/cm also leads on in-app purchases (none vs 2) and price ($0.99 vs $7.99). On ads, device support and iOS requirement there is nothing between them.

coolAltitude costs $7.99 and Simple Ruler inch/cm $0.99 up front. coolAltitude sells 2 in-app purchases, starting at $7.99 per year. Simple Ruler inch/cm asks for nothing beyond the download.

coolAltitude ships an update every 3 months, Simple Ruler inch/cm daily. The most recent releases landed on November 7, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | coolAltitude | Simple Ruler inch/cm |
| --- | --- | --- |
| Price | $7.99 | **$0.99** |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/coolaltitude-pilot-tools/id641533221/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 60.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Daily** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 56 MB | 1 MB |
| Requires iOS | 17.0 | **16.1** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [SilkIdea s.r.o.](https://appshunter.io/developer/413936304) | [Systemiko Inc.](https://appshunter.io/developer/680630947) |

## What reviewers say

### coolAltitude

[App page](https://appshunter.io/ios/app/coolaltitude-pilot-tools/id641533221)

This app provides pilots with essential tools for cold-temperature altitude corrections, approach profiles, and de-icing calculations. It integrates weather data and offers a clear interface for critical flight planning information.

**Highlights:** Cold-temperature altitude corrections, Approach profile visualization, De-icing and holdover time calculations, FMS-style approach setup, METAR, TAF, and runway condition integration, Light and dark mode support

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| De & Anti-Icing Pro | $7.99 | per year |
| Save & Retrieve Approach Data | $7.99 | per year |


### Simple Ruler inch/cm

[App page](https://appshunter.io/ios/app/simple-ruler-inchcm/id6479048575)

This utility transforms your iPhone into a precise on-screen ruler for measuring in inches and centimeters. It offers a simple interface for quick measurements, serving as a handy tool for various tasks.

**Highlights:** On-screen ruler, Inch measurement, Centimeter measurement, Simple interface, Accurate measurements

**In-app purchases:** none


## Frequently asked questions

### Is coolAltitude free?

coolAltitude costs $7.99, and also offers in-app purchases.

### Is Simple Ruler inch/cm free?

Simple Ruler inch/cm costs $0.99, with no in-app purchases.

### Do coolAltitude or Simple Ruler inch/cm have ads?

Neither coolAltitude nor Simple Ruler inch/cm shows ads.

### Which is updated more often, coolAltitude or Simple Ruler inch/cm?

coolAltitude ships an update every 3 months, and Simple Ruler inch/cm daily. Most recently, coolAltitude was updated on November 7, 2026 and Simple Ruler inch/cm on November 4, 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.*