# IS RT vs WeldMaster

The clearest difference is in-app purchases: IS RT at none against WeldMaster's 4. IS RT also leads on ads (none vs shown) and iOS requirement (15.6 vs 17.0). WeldMaster's advantage is update cadence (every 9 days vs every 5 months). On price and device support there is nothing between them.

Both are free to download. WeldMaster sells 4 in-app purchases, starting at $0.99 per 7 days. IS RT asks for nothing beyond the download.

IS RT ships an update every 5 months, WeldMaster every 9 days. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | IS RT | WeldMaster |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | **Every 9 days** |
| Size | 28 MB | 7 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [Institut de Soudure](https://appshunter.io/developer/1735474226) | [Grima Hdez](https://appshunter.io/developer/1741481582) |

## What reviewers say

### IS RT

[App page](https://appshunter.io/ios/app/is-rt/id6479296879)

**Features:** macOS Compatibility

**In-app purchases:** none


### WeldMaster

[App page](https://appshunter.io/ios/app/weldmaster-welding-calculator/id6790162809)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| WeldMaster Pro Weekly | $0.99 | per 7 days |
| WeldMaster Pro Monthly | $1.99 | per month |
| WeldMaster Pro Yearly | $2.99 | per year |
| WeldMaster Pro | $4.99 | one-time |


## Frequently asked questions

### Is IS RT free?

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

### Is WeldMaster free?

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

### Do IS RT or WeldMaster have ads?

WeldMaster shows ads; IS RT does not.

### Which is updated more often, IS RT or WeldMaster?

IS RT ships an update every 5 months, and WeldMaster every 9 days. Most recently, IS RT was updated on October 25, 2026 and WeldMaster on October 24, 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.*