# Hangar vs GTP API Gravity Calculator2

The clearest difference is price: Hangar at Free against GTP API Gravity Calculator2's $9.99. Hangar also leads on rating (4.9 vs 4.0) and update cadence (every 5 days vs every 2 months). GTP API Gravity Calculator2's advantage is review sentiment (100% vs 64%) and in-app purchases (none vs 12). On device support there is nothing between them.

Hangar is free to download; GTP API Gravity Calculator2 costs $9.99 up front. Hangar sells 12 in-app purchases, starting at $3.99 per 7 days. GTP API Gravity Calculator2 asks for nothing beyond the download.

Hangar holds the better App Store score, 4.9 against 4.0. That said, the two scores are not equally well evidenced: Hangar has 1.1K ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 64% of Hangar's written reviews are positive against 100% of GTP API Gravity Calculator2's, so the app with the better star average is not the one people write more warmly about.

Hangar ships an update every 5 days, GTP API Gravity Calculator2 every 2 months. The most recent releases landed on September 24, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Hangar | GTP API Gravity Calculator2 |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | **[4.9 (1.1K ratings)](https://appshunter.io/ios/app/hangar-social-flight-tracker/id6468550769/reviews)** | [4.0 (1 ratings)](https://appshunter.io/ios/app/gtp-api-gravity-calculator2/id6742924006/reviews) |
| Number of ratings | **1.1K** | 1 |
| Positive reviews | 63.9% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 5 days** | Every 2 months |
| Monetization | **Free with in-app purchases** | Paid |
| Best chart rank | — | **#193** |
| Size | 142 MB | 9 MB |
| Requires iOS | 18.2 | **12.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Fly Hangar, LLC](https://appshunter.io/developer/1710080060) | [Gammon Technical Products](https://appshunter.io/developer/1163782116) |

## What reviewers say

### Hangar

[App page](https://appshunter.io/ios/app/hangar-social-flight-tracker/id6468550769)

This app is a flight tracking and social platform for pilots. It automatically logs flights, allows sharing of journeys, and helps discover new airports with detailed information. Relive flights with 3D replays and manage your pilot profile.

**Highlights:** Automatic flight logging, Manual flight logging with ADS-B data, Flight sharing and 3D replays, Airport discovery with amenities, Pilot profile management, Real-time flight notifications, Export to LogTen Pro

**In-app purchases (12)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hangar Pro Weekly | $3.99 | per 7 days |
| Weekly | $5.99 | per 7 days |
| Monthly Subscription | $5.99 | per month |
| Hangar Plus Monthly | $6.99 | per month |
| Hangar Pro Monthly | $7.99 | per month |
| Monthly | $9.99 | per month |
| Hangar Family Monthly | $15.99 | per month |
| Annual Subscription | $59.99 | per year |
| Annual | $69.99 | per year |
| Hangar Pro Annual | $69.99 | per year |
| Hangar Plus Annual | $89.99 | per year |
| Hangar Family Annual | $139.99 | per year |

**What reviewers like**

- 👍 Easy to set up and use
- 🚀 Intuitive and responsive
- 💡 Unique way to connect with aviation community
- 🤝 Great for networking and sharing experiences
- 🛩️ Helpful for pilots at any stage

**What reviewers complain about**

- 🐛 Buggy and glitchy
- 💰 Subscription model not clearly communicated
- 🤖 Pushy monetization tactics
- 🤔 Lacking in key features and functionality

**Reported bugs**

- Login/registration issues
- Profile picture uploads not working
- Notification taps not taking users to relevant content
- Following feed not updating properly

**Requested features**

- Add more aircraft types and smaller airfields
- Improve notification system and in-app navigation
- Implement a 'help' section for feedback and feature ideas
- Allow users to add custom locations and aircraft


### 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 Hangar free?

Hangar is free to download, with in-app purchases available.

### Is GTP API Gravity Calculator2 free?

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

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

Hangar is rated higher. Hangar averages 4.9 out of 5 from 1.1K ratings, while GTP API Gravity Calculator2 averages 4.0 from 1 ratings.

### Do Hangar or GTP API Gravity Calculator2 have ads?

Hangar shows ads; GTP API Gravity Calculator2 does not.

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

Hangar ships an update every 5 days, and GTP API Gravity Calculator2 every 2 months. Most recently, Hangar was updated on September 24, 2026 and GTP API Gravity Calculator2 on September 8, 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.*