# Pipe Fitting & ASME Toolbox vs UnitDown AI

The clearest difference is update cadence: UnitDown AI at every 4 days against Pipe Fitting & ASME Toolbox's every 4 months. Pipe Fitting & ASME Toolbox's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Pipe Fitting & ASME Toolbox sells 1 one-off in-app purchase and UnitDown AI sells 3 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Pipe Fitting & ASME Toolbox ships an update every 4 months, UnitDown AI every 4 days. The most recent releases landed on October 28, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Pipe Fitting & ASME Toolbox | UnitDown AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (21 ratings)](https://appshunter.io/ios/app/pipe-fitting-and-asme-toolbox/id6752763143/reviews)** | — |
| Number of ratings | **21** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 210 MB | 8 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ashvin Kevadiya](https://appshunter.io/developer/1756324971) | [JESUS ESCAMEA](https://appshunter.io/developer/1896505910) |

## What reviewers say

### Pipe Fitting & ASME Toolbox

[App page](https://appshunter.io/ios/app/pipe-fitting-and-asme-toolbox/id6752763143)

Access essential piping engineering data, standards, and smart calculators for professionals and students. Covers ASME standards, pipe and flange dimensions, fitting details, and valve sizes. Includes daily tips and quizzes to enhance knowledge.

**Highlights:** Engineering calculators, Piping data and standards, Pipe dimensions, Flange dimensions, Fitting dimensions, Valve dimensions, Daily tips and quiz

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Premium | $9.99 | one-time |


### UnitDown AI

[App page](https://appshunter.io/ios/app/unitdown-ai/id6767750626)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| UnitDown AI Pro | $4.99 | per month |
| UnitDown Pro Monthly | $9.99 | per month |
| UnitDown Pro Annual | $39.99 | per year |


## Frequently asked questions

### Is Pipe Fitting & ASME Toolbox free?

Pipe Fitting & ASME Toolbox is free to download, with in-app purchases available.

### Is UnitDown AI free?

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

### Do Pipe Fitting & ASME Toolbox or UnitDown AI have ads?

Neither Pipe Fitting & ASME Toolbox nor UnitDown AI shows ads.

### Which is updated more often, Pipe Fitting & ASME Toolbox or UnitDown AI?

Pipe Fitting & ASME Toolbox ships an update every 4 months, and UnitDown AI every 4 days. Most recently, Pipe Fitting & ASME Toolbox was updated on October 28, 2026 and UnitDown AI on October 25, 2026.

---

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