# Brain vs Reverse PET

The clearest difference is in-app purchases: Reverse PET at none against Brain's 1. Reverse PET also leads on update cadence (every 6 weeks vs every 9 months). Brain's advantage is iOS requirement (15.0 vs 18.0). On price, ads and device support there is nothing between them.

Both are free to download. Brain sells 1 one-off in-app purchase. Reverse PET asks for nothing beyond the download.

Brain ships an update every 9 months, Reverse PET every 6 weeks. The most recent releases landed on October 1, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Brain | Reverse PET |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 6 weeks** |
| Size | 91 MB | 29 MB |
| Requires iOS | **15.0** | 18.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [BRAINX ACADEMY SRL](https://appshunter.io/developer/1747678278) | [Reverse PET S.R.L.](https://appshunter.io/developer/1758604598) |

## What reviewers say

### Brain

[App page](https://appshunter.io/ios/app/brain-x/id6502986082)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Result | $1.99 | one-time |


### Reverse PET

[App page](https://appshunter.io/ios/app/reverse-pet/id6563147364)

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

**In-app purchases:** none


## Frequently asked questions

### Is Brain free?

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

### Is Reverse PET free?

Reverse PET is free to download, with no in-app purchases.

### Do Brain or Reverse PET have ads?

Neither Brain nor Reverse PET shows ads.

### Which is updated more often, Brain or Reverse PET?

Brain ships an update every 9 months, and Reverse PET every 6 weeks. Most recently, Brain was updated on October 1, 2026 and Reverse PET on October 12, 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.*