# Transformer Calculation Tool vs E

The clearest difference is ads: Transformer Calculation Tool at none against E's shown. Transformer Calculation Tool also leads on iOS requirement (13.0 vs 15.0). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. Transformer Calculation Tool sells 1 one-off in-app purchase and E sells 3 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

Transformer Calculation Tool ships an update every 4 weeks, E every 3 weeks. The most recent releases landed on September 16, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | Transformer Calculation Tool | E |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 weeks | **Every 3 weeks** |
| Size | 57 MB | 37 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Shraddhaben Parmar](https://appshunter.io/developer/1889769325) | [Mohamed Mubarak](https://appshunter.io/developer/6787548629) |

## What reviewers say

### Transformer Calculation Tool

[App page](https://appshunter.io/ios/app/transformer-calculation-tool/id6772152007)

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

**In-app purchases (1)**

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


### E

[App page](https://appshunter.io/ios/app/e-light-circuit-simulator/id6787548627)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $2.99 | per month |
| Pro Quarterly | $7.99 | per 3 months |
| Pro Yearly | $24.99 | per year |


## Frequently asked questions

### Is Transformer Calculation Tool free?

Transformer Calculation Tool is free to download, with in-app purchases available.

### Is E free?

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

### Do Transformer Calculation Tool or E have ads?

E shows ads; Transformer Calculation Tool does not.

### Which is updated more often, Transformer Calculation Tool or E?

Transformer Calculation Tool ships an update every 4 weeks, and E every 3 weeks. Most recently, Transformer Calculation Tool was updated on September 16, 2026 and E on September 29, 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.*