# CPF TechTools vs Dr Underhood Live Assist

The clearest difference is in-app purchases: CPF TechTools at none against Dr Underhood Live Assist's 2. Dr Underhood Live Assist's advantage is update cadence (weekly vs every 2 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Dr Underhood Live Assist sells 2 one-off in-app purchases. CPF TechTools asks for nothing beyond the download.

CPF TechTools ships an update every 2 months, Dr Underhood Live Assist weekly. The most recent releases landed on November 1, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | CPF TechTools | Dr Underhood Live Assist |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (23 ratings)](https://appshunter.io/ios/app/cpf-techtools/id679297384/reviews)** | — |
| Number of ratings | **23** | — |
| Positive reviews | 54.5% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | Free | — |
| Size | 8 MB | 43 MB |
| Requires iOS | **14.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Charlotte Pipe and Foundry Company](https://appshunter.io/developer/679297387) | [Rob Holmes](https://appshunter.io/developer/1896148821) |

## What reviewers say

### CPF TechTools

[App page](https://appshunter.io/ios/app/cpf-techtools/id679297384)

This app offers essential on-the-go technical calculators for plumbing professionals. It includes tools for expansion/contraction and temperature de-rating, with more features planned for future updates.

**Highlights:** Expansion calculator, Contraction calculator, Temperature de-rating calculator, Tools for plumbing professionals, Future tool additions planned

**Features:** macOS Compatibility

**In-app purchases:** none


### Dr Underhood Live Assist

[App page](https://appshunter.io/ios/app/dr-underhood-live-assist/id6782738561)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic Diagnosis Unlock | $19.99 | one-time |
| Advanced Diagnosis Unlock | $99.99 | one-time |


## Frequently asked questions

### Is CPF TechTools free?

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

### Is Dr Underhood Live Assist free?

Dr Underhood Live Assist is free to download, with in-app purchases available.

### Do CPF TechTools or Dr Underhood Live Assist have ads?

Neither CPF TechTools nor Dr Underhood Live Assist shows ads.

### Which is updated more often, CPF TechTools or Dr Underhood Live Assist?

CPF TechTools ships an update every 2 months, and Dr Underhood Live Assist weekly. Most recently, CPF TechTools was updated on November 1, 2026 and Dr Underhood Live Assist on October 25, 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.*