# GB Gas Ventilation Calculator vs Gas Engineer Software

The clearest difference is review sentiment: Gas Engineer Software at 85% against GB Gas Ventilation Calculator's 0%. Gas Engineer Software also leads on price (Free vs $3.99) and update cadence (weekly vs every 14 months). GB Gas Ventilation Calculator's advantage is in-app purchases (none vs 1). On ads and device support there is nothing between them.

Gas Engineer Software is free to download; GB Gas Ventilation Calculator costs $3.99 up front. Gas Engineer Software sells 1 one-off in-app purchase. GB Gas Ventilation Calculator asks for nothing beyond the download.

GB Gas Ventilation Calculator ships an update every 14 months, Gas Engineer Software weekly. Both last shipped on October 29, 2026.

## The numbers

| Metric | GB Gas Ventilation Calculator | Gas Engineer Software |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Positive reviews | 0.0% of reviews | **84.8% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 14 months | **Weekly** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 3 MB | 194 MB |
| Requires iOS | 26.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [GB-GAS.CO.UK](https://appshunter.io/developer/425897007) | [Software Works for You Ltd](https://appshunter.io/developer/771853288) |

## What reviewers say

### GB Gas Ventilation Calculator

[App page](https://appshunter.io/ios/app/gb-gas-ventilation-calculator/id426220160)

Calculate ventilation requirements for gas appliances, including open flued, room sealed, and flueless types. Determine free air area for existing and new vents to ensure suitability for appliances. Simplifies complex calculations by reading appliance data directly.

**Highlights:** Ventilation calculations for gas appliances, Supports open flued, room sealed, and flueless types, Calculates for multiple appliances in one room, Determines free air area of vents, Reads appliance data directly

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

**In-app purchases:** none


### Gas Engineer Software

[App page](https://appshunter.io/ios/app/gas-engineer-software-ges/id771853285)

This comprehensive app helps gas, oil, and plumbing professionals streamline their business operations. It allows for the creation of industry-specific certificates, issuance of quotes and invoices, and efficient job scheduling. Manage your team, customers, and finances from any device, anywhere, saving time and boosting revenue.

**Highlights:** Create industry certificates, Issue quotes and invoices, Schedule jobs with calendar, Manage team and customers, Automated service reminders, Offline access

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Single Engineer - 12 Months Subscription | $19.00 | one-time |

**What reviewers like**

- 👍 Easy to use
- ⏱️ Time saver
- 💼 Professional appearance
- 📈 Scales with business growth
- 🛠️ Reliable day-to-day

**What reviewers complain about**

- 💰 Price keeps increasing
- 📉 No real improvement seen
- 😠 Greed perceived
- ⚠️ Unexpected maintenance
- ✍️ Small font size

**Reported bugs**

- Unexpected site shutdowns
- Syncing is slow
- Glitches in invoicing following a job report
- App has become very slow due to latest update
- Not usable at present time

**Requested features**

- Add multiple picture attachments
- Select several photos at once
- Flag jobs as finished
- Oil forms for non-OFTEC registered companies
- Calculate pipe work volume and purge volume


## Frequently asked questions

### Is GB Gas Ventilation Calculator free?

GB Gas Ventilation Calculator costs $3.99, with no in-app purchases.

### Is Gas Engineer Software free?

Gas Engineer Software is free to download, with in-app purchases available.

### Do GB Gas Ventilation Calculator or Gas Engineer Software have ads?

Neither GB Gas Ventilation Calculator nor Gas Engineer Software shows ads.

### Which is updated more often, GB Gas Ventilation Calculator or Gas Engineer Software?

GB Gas Ventilation Calculator ships an update every 14 months, and Gas Engineer Software weekly. Most recently, GB Gas Ventilation Calculator was updated on October 29, 2026 and Gas Engineer Software on October 29, 2026.

---

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