# What Gas? vs TrainPost

What Gas? and TrainPost are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

## The numbers

| Metric | What Gas? | TrainPost |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/what-gas/id1230722190/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 37 months | — |
| Monetization | Free | — |
| Size | 24 MB | 70 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [UNEP](https://appshunter.io/developer/1106793919) | [Universal Postal Union](https://appshunter.io/developer/1518466197) |

## What reviewers say

### What Gas?

[App page](https://appshunter.io/ios/app/what-gas/id1230722190)

This tool helps identify refrigerant gases, including ozone-depleting substances and their alternatives. It provides detailed information on chemical properties, hazards, and regulatory status for customs officers and technicians.

**Highlights:** Refrigerant gas identification, Information on ODS and alternatives, Details on ODP and GWP values, Searchable database, Flammability and hazard information, Montreal Protocol compliance data, Available in French and Spanish

**Features:** macOS Compatibility

**In-app purchases:** none


### TrainPost

[App page](https://appshunter.io/ios/app/trainpost/id6737562660)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is What Gas? free?

What Gas? is free to download, with no in-app purchases.

### Is TrainPost free?

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

### Do What Gas? or TrainPost have ads?

Neither What Gas? nor TrainPost shows ads.

---

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