NDX Inspections vs GTP API Gravity Calculator2
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
NDX Inspections
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.
- Mobile and web dashboard
- Inspection status tracking
- Trend recognition
- Insightful report generation
- Compliance with audits
- Replaces manual methods
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The intuitive interface offers a mobile and web dashboard experience, allowing users to complete inspections, recognize trends, and develop insightful reports. NDX Inspections tracks inspection status, alerts the users of inspection failures or misses, and complies with mandated audits. The platform is designed to directly replace traditional pencil and paper methods, while providing valuable insights on top of ATA103 and JIG 1/2/4 requirements.
GTP API Gravity Calculator2
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.
- Corrected API gravity calculation
- Total fuel weight calculation
- Supports jet, gasoline, and diesel fuels
- Digital version of slide calculators
- Developed in 2025
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The GTP API Gravity Calculator v2 (Developed 2025) from Gammon Technical Products, Inc. provides users the ability to determine corrected API at 60 Deg F for jet, gasoline, and diesel fuels. The calculator is a digital version of our GTP-3012-1A and GTP-2727EF slide calculators and it also is capable of calculating the total weight of the fuel.
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | NDX Inspections | GTP API Gravity Calculator2 |
|---|---|---|
| Price | Free — better | $9.99 |
| Rating | 4.5 (13 ratings) — better | 4.0 (1 ratings) |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 13 — better | 1 |
| Update frequency | Every 3 weeks — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Best chart rank | — | #193 — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 62 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | NDX LLC | Gammon Technical Products |
Customer experience
NDX Inspections
GTP API Gravity Calculator2
In-app purchases
NDX Inspections
No in-app purchases
GTP API Gravity Calculator2
No in-app purchases
Questions
Is NDX Inspections free?
Is GTP API Gravity Calculator2 free?
Which has better reviews, NDX Inspections or GTP API Gravity Calculator2?
Do NDX Inspections or GTP API Gravity Calculator2 have ads?
Which is updated more often, NDX Inspections or GTP API Gravity Calculator2?
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