# PreHeat vs Touch Trigonometry

The clearest difference is device support: PreHeat at 4 against Touch Trigonometry's 2. PreHeat also leads on iOS requirement (13.0 vs 15.1). On price, ads and in-app purchases there is nothing between them.

Both are free to download. PreHeat sells 1 one-off in-app purchase and Touch Trigonometry sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | PreHeat | Touch Trigonometry |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | — |
| Size | 4 MB | 48 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Shabbir Ahmed](https://appshunter.io/developer/1083166021) | [Aisatsu LLC](https://appshunter.io/developer/1874553323) |

## What reviewers say

### PreHeat

[App page](https://appshunter.io/ios/app/preheat/id6461216985)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Non Consumable Subscription | $3.99 | one-time |


### Touch Trigonometry

[App page](https://appshunter.io/ios/app/touch-trigonometry/id6758712159)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Touch Trigonometry | $4.99 | one-time |


## Frequently asked questions

### Is PreHeat free?

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

### Is Touch Trigonometry free?

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

### Do PreHeat or Touch Trigonometry have ads?

Neither PreHeat nor Touch Trigonometry shows ads.

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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.*