# LIVING OZONE vs GTP API Gravity Calculator2

The clearest difference is price: LIVING OZONE at Free against GTP API Gravity Calculator2's $9.99. LIVING OZONE also leads on iOS requirement (10.0 vs 12.0). GTP API Gravity Calculator2's advantage is chart position (#176 vs unranked). On ads, in-app purchases and device support there is nothing between them.

LIVING OZONE is free to download; GTP API Gravity Calculator2 costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | LIVING OZONE | GTP API Gravity Calculator2 |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | — | **[4.0 (1 ratings)](https://appshunter.io/ios/app/gtp-api-gravity-calculator2/id6742924006/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | — | Every 2 months |
| Monetization | — | Paid |
| Best chart rank | — | **#176** |
| Size | 36 MB | 9 MB |
| Requires iOS | **10.0** | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [红奎 刘](https://appshunter.io/developer/1465054112) | [Gammon Technical Products](https://appshunter.io/developer/1163782116) |

## What reviewers say

### LIVING OZONE

[App page](https://appshunter.io/ios/app/living-ozone/id6478916119)

**Features:** macOS Compatibility

**In-app purchases:** none


### GTP API Gravity Calculator2

[App page](https://appshunter.io/ios/app/gtp-api-gravity-calculator2/id6742924006)

**Currently charting:** #176 Top Paid · Utilities (US App Store)

This application calculates the corrected API gravity at 60°F for jet, gasoline, and diesel fuels. It also determines the total weight of the fuel. It's a digital replacement for physical slide calculators.

**Highlights:** Corrected API gravity calculation, Total fuel weight calculation, Supports jet, gasoline, and diesel fuels, Digital version of slide calculators, Developed in 2025

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

**In-app purchases:** none


## Frequently asked questions

### Is LIVING OZONE free?

LIVING OZONE is free to download, with no in-app purchases.

### Is GTP API Gravity Calculator2 free?

GTP API Gravity Calculator2 costs $9.99, with no in-app purchases.

### Do LIVING OZONE or GTP API Gravity Calculator2 have ads?

Neither LIVING OZONE nor GTP API Gravity Calculator2 shows ads.

---

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