# Petatto TODO vs Second Brain

The clearest difference is update cadence: Second Brain at every 2 days against Petatto TODO's every 8 days. Petatto TODO's advantage is iOS requirement (15.1 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Petatto TODO ships an update every 8 days, Second Brain every 2 days. The most recent releases landed on October 6, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Petatto TODO | Second Brain |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 8 days | **Every 2 days** |
| Size | 84 MB | 26 MB |
| Requires iOS | **15.1** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [MARIE MORIKAGE](https://appshunter.io/developer/1896645636) | [kim dahye](https://appshunter.io/developer/1868391710) |

## What reviewers say

### Petatto TODO

[App page](https://appshunter.io/ios/app/petatto-todo/id6771369990)

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

**In-app purchases:** none


### Second Brain

[App page](https://appshunter.io/ios/app/second-brain-ai-note/id6799343264)

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

**In-app purchases:** none


## Frequently asked questions

### Is Petatto TODO free?

Petatto TODO is free to download, with no in-app purchases.

### Is Second Brain free?

Second Brain is free to download, with no in-app purchases.

### Do Petatto TODO or Second Brain have ads?

Neither Petatto TODO nor Second Brain shows ads.

### Which is updated more often, Petatto TODO or Second Brain?

Petatto TODO ships an update every 8 days, and Second Brain every 2 days. Most recently, Petatto TODO was updated on October 6, 2026 and Second Brain on October 10, 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.*