# NDX Inspections vs GTP API Gravity Calculator2

The clearest difference is price: NDX Inspections at Free against GTP API Gravity Calculator2's $9.99. NDX Inspections also leads on rating (4.5 vs 4.0) and update cadence (every 3 weeks vs every 2 months). GTP API Gravity Calculator2's advantage is chart position (#193 vs unranked) and iOS requirement (12.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

NDX Inspections 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.

NDX Inspections holds the better App Store score, 4.5 against 4.0. That said, the two scores are not equally well evidenced: NDX Inspections has 13 ratings behind it against 1, so its average is the more settled of the two.

NDX Inspections ships an update every 3 weeks, GTP API Gravity Calculator2 every 2 months. The most recent releases landed on September 14, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | NDX Inspections | GTP API Gravity Calculator2 |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | **[4.5 (13 ratings)](https://appshunter.io/ios/app/ndx-inspections/id6474188152/reviews)** | [4.0 (1 ratings)](https://appshunter.io/ios/app/gtp-api-gravity-calculator2/id6742924006/reviews) |
| Number of ratings | **13** | 1 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | **Free** | Paid |
| Best chart rank | — | **#193** |
| Size | 62 MB | 9 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [NDX LLC](https://appshunter.io/developer/1720955127) | [Gammon Technical Products](https://appshunter.io/developer/1163782116) |

## What reviewers say

### NDX Inspections

[App page](https://appshunter.io/ios/app/ndx-inspections/id6474188152)

Streamline your inspection process with a mobile and web dashboard. Track status, identify trends, and generate reports to replace manual methods and ensure compliance with industry standards.

**Highlights:** Mobile and web dashboard, Inspection status tracking, Trend recognition, Insightful report generation, Compliance with audits, Replaces manual methods

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

**In-app purchases:** none


### GTP API Gravity Calculator2

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

**Currently charting:** #193 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 NDX Inspections free?

NDX Inspections 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.

### Which has better reviews, NDX Inspections or GTP API Gravity Calculator2?

NDX Inspections is rated higher. NDX Inspections averages 4.5 out of 5 from 13 ratings, while GTP API Gravity Calculator2 averages 4.0 from 1 ratings.

### Do NDX Inspections or GTP API Gravity Calculator2 have ads?

Neither NDX Inspections nor GTP API Gravity Calculator2 shows ads.

### Which is updated more often, NDX Inspections or GTP API Gravity Calculator2?

NDX Inspections ships an update every 3 weeks, and GTP API Gravity Calculator2 every 2 months. Most recently, NDX Inspections was updated on September 14, 2026 and GTP API Gravity Calculator2 on September 8, 2026.

---

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