# Gammon API Gravity Calculator vs S61 PPC

The clearest difference is price: S61 PPC at $2.99 against Gammon API Gravity Calculator's $9.99. Gammon API Gravity Calculator's advantage is chart position (#38 vs unranked) and iOS requirement (8.0 vs 16.6). On ads, in-app purchases and device support there is nothing between them.

Gammon API Gravity Calculator costs $9.99 and S61 PPC $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | Gammon API Gravity Calculator | S61 PPC |
| --- | --- | --- |
| Price | $9.99 | **$2.99** |
| Rating | **[3.6 (10 ratings)](https://appshunter.io/ios/app/gammon-api-gravity-calculator/id1163782117/reviews)** | — |
| Number of ratings | **10** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | — | Every 48 months |
| Monetization | Paid | — |
| Best chart rank | **#38** | — |
| Size | 10 MB | 2 MB |
| Requires iOS | **8.0** | 16.6 |
| Devices | iPhone, iPod | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Gammon Technical Products](https://appshunter.io/developer/1163782116) | [Arsenal Dev LLC](https://appshunter.io/developer/1559628965) |

## What reviewers say

### Gammon API Gravity Calculator

[App page](https://appshunter.io/ios/app/gammon-api-gravity-calculator/id1163782117)

**Currently charting:** #38 Top Paid · Reference (US App Store)

Calculate corrected API gravity for jet, gasoline, and diesel fuels at 60°F. This digital tool also determines the total weight of the fuel, replicating the functionality of physical slide calculators.

**Highlights:** Corrected API gravity calculation, Fuel weight calculation, Supports jet, gasoline, and diesel fuels, Digital slide calculator replacement, Accurate at 60°F

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

**In-app purchases:** none


### S61 PPC

[App page](https://appshunter.io/ios/app/s61-ppc/id1559628963)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Gammon API Gravity Calculator free?

Gammon API Gravity Calculator costs $9.99, with no in-app purchases.

### Is S61 PPC free?

S61 PPC costs $2.99, with no in-app purchases.

### Do Gammon API Gravity Calculator or S61 PPC have ads?

Neither Gammon API Gravity Calculator nor S61 PPC shows ads.

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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.*