# Transformer Calculator Plus vs Drive Diagnostics

The clearest difference is price: Drive Diagnostics at Free against Transformer Calculator Plus's $2.99. Drive Diagnostics also leads on update cadence (every 6 months vs every 45 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Drive Diagnostics is free to download; Transformer Calculator Plus costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Transformer Calculator Plus ships an update every 45 months, Drive Diagnostics every 6 months. Both last shipped on October 14, 2026.

## The numbers

| Metric | Transformer Calculator Plus | Drive Diagnostics |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[3.3 (4 ratings)](https://appshunter.io/ios/app/transformer-calculator-plus/id1372528401/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 45 months | **Every 6 months** |
| Monetization | Paid | — |
| Size | 1 MB | 9 MB |
| Requires iOS | **13.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Bonfiglioli SPA](https://appshunter.io/developer/670210180) |

## What reviewers say

### Transformer Calculator Plus

[App page](https://appshunter.io/ios/app/transformer-calculator-plus/id1372528401)

This utility app calculates key parameters for transformers, including voltage, current, and turns ratio. It helps determine if a transformer is step-up or step-down, essential for power conversion applications.

**Highlights:** Calculate primary and secondary voltage, Calculate primary and secondary current, Calculate transformer turns ratio, Determine step-up or step-down transformer, Supports AC voltage calculations

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

**In-app purchases:** none


### Drive Diagnostics

[App page](https://appshunter.io/ios/app/drive-diagnostics/id1523617166)

**In-app purchases:** none


## Frequently asked questions

### Is Transformer Calculator Plus free?

Transformer Calculator Plus costs $2.99, with no in-app purchases.

### Is Drive Diagnostics free?

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

### Do Transformer Calculator Plus or Drive Diagnostics have ads?

Neither Transformer Calculator Plus nor Drive Diagnostics shows ads.

### Which is updated more often, Transformer Calculator Plus or Drive Diagnostics?

Transformer Calculator Plus ships an update every 45 months, and Drive Diagnostics every 6 months. Most recently, Transformer Calculator Plus was updated on October 14, 2026 and Drive Diagnostics on October 14, 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.*