# One Big Thing vs ADHD Focus

The clearest difference is in-app purchases: One Big Thing at none against ADHD Focus's 2. ADHD Focus's advantage is update cadence (every 3 days vs every 2 months) and device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

Both are free to download. ADHD Focus sells 2 in-app purchases, starting at $1.99 per 7 days. One Big Thing asks for nothing beyond the download.

One Big Thing ships an update every 2 months, ADHD Focus every 3 days. The most recent releases landed on October 30, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | One Big Thing | ADHD Focus |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 days** |
| Size | 1 MB | 32 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | iPhone | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Thomas Chatting](https://appshunter.io/developer/1811425476) | [Appgineering GbR](https://appshunter.io/developer/1785233826) |

## What reviewers say

### One Big Thing

[App page](https://appshunter.io/ios/app/one-big-thing/id6745229950)

**Features:** macOS Compatibility

**In-app purchases:** none


### ADHD Focus

[App page](https://appshunter.io/ios/app/adhd-focus-that-one-thing/id6746286274)

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ThatOneThing Premium (1 week) | $1.99 | per 7 days |
| ThatOneThing Premium (1 year) | $3.99 | per year |


## Frequently asked questions

### Is One Big Thing free?

One Big Thing is free to download, with no in-app purchases.

### Is ADHD Focus free?

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

### Do One Big Thing or ADHD Focus have ads?

Neither One Big Thing nor ADHD Focus shows ads.

### Which is updated more often, One Big Thing or ADHD Focus?

One Big Thing ships an update every 2 months, and ADHD Focus every 3 days. Most recently, One Big Thing was updated on October 30, 2026 and ADHD Focus on October 25, 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.*