# GDU Calculator vs Fly PHX

The clearest difference is rating: Fly PHX at 5.0 against GDU Calculator's 2.5. Fly PHX also leads on iOS requirement (11.0 vs 13.0). GDU Calculator's advantage is ads (none vs shown) and update cadence (every 6 weeks vs every 6 months). On price, ratings volume and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Fly PHX holds the better App Store score, 5.0 against 2.5. Both are backed by a comparable volume of ratings — 11 and 4 respectively.

GDU Calculator ships an update every 6 weeks, Fly PHX every 6 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | GDU Calculator | Fly PHX |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.5 (11 ratings)](https://appshunter.io/ios/app/gdu-calculator/id850528308/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/fly-phx/id1254570396/reviews)** |
| Number of ratings | **11** | 4 |
| Positive reviews | 25.0% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 6 weeks** | Every 6 months |
| Monetization | **Free** | Ad-supported |
| Size | 57 MB | 77 MB |
| Requires iOS | 13.0 | **11.0** |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | +4 | 4+ |
| Developer | [Ag PhD](https://appshunter.io/developer/520210329) | [Sentera, Inc.](https://appshunter.io/developer/1059785015) |

## What reviewers say

### GDU Calculator

[App page](https://appshunter.io/ios/app/gdu-calculator/id850528308)

This app helps corn and wheat growers calculate Growing Degree Units (GDUs) for their crops. It provides daily temperature and GDU data, and can send push notifications about potential field issues based on crop growth stages.

**Highlights:** Growing Degree Unit calculation, Corn and wheat crop support, Day-by-day temperature data, Push notifications for field issues, Crop growth stage tracking

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

**In-app purchases:** none


### Fly PHX

[App page](https://appshunter.io/ios/app/fly-phx/id1254570396)

This application enables pilots to easily operate a drone for capturing high-resolution aerial imagery. It facilitates pre-flight planning, real-time flight control, and communication with onboard sensors. The captured data can be used for detailed analysis and reporting on crop health.

**Highlights:** Real-time sensor communication, Pre-flight planning tools, Survey area visualization, Sentera PHX flight control, Data for FieldAgent platform

**In-app purchases:** none


## Frequently asked questions

### Is GDU Calculator free?

GDU Calculator is free to download, with no in-app purchases.

### Is Fly PHX free?

Fly PHX is free to download, with no in-app purchases.

### Which has better reviews, GDU Calculator or Fly PHX?

Fly PHX is rated higher. GDU Calculator averages 2.5 out of 5 from 11 ratings, while Fly PHX averages 5.0 from 4 ratings.

### Do GDU Calculator or Fly PHX have ads?

Fly PHX shows ads; GDU Calculator does not.

### Which is updated more often, GDU Calculator or Fly PHX?

GDU Calculator ships an update every 6 weeks, and Fly PHX every 6 months. Most recently, GDU Calculator was updated on November 1, 2026 and Fly PHX on November 2, 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.*