# One Question Journal vs Diffu

The clearest difference is in-app purchases: One Question Journal at none against Diffu's 6. One Question Journal also leads on ads (none vs shown) and update cadence (weekly vs every 2 weeks). Diffu's advantage is iOS requirement (15.0 vs 26.2). On price and device support there is nothing between them.

Both are free to download. Diffu sells 6 in-app purchases, starting at $2.99 per month. One Question Journal asks for nothing beyond the download.

One Question Journal ships an update weekly, Diffu every 2 weeks. The most recent releases landed on October 9, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | One Question Journal | Diffu |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Weekly** | Every 2 weeks |
| Size | 13 MB | 73 MB |
| Requires iOS | 26.2 | **15.0** |
| Devices | **iPhone, iPad, Apple Watch, Vision Pro** | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Waseef Akhtar](https://appshunter.io/developer/1877652451) | [Jeong-Hwan Jang](https://appshunter.io/developer/1880755654) |

## What reviewers say

### One Question Journal

[App page](https://appshunter.io/ios/app/one-question-journal/id6759250351)

**Features:** macOS Compatibility, Apple Watch app

**In-app purchases:** none


### Diffu

[App page](https://appshunter.io/ios/app/diffu-something-to-say/id6759802088)

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Diffu Premium | $2.99 | per month |
| Diffu Premium | $29.99 | per year |
| 100 엠버 | $0.49 | one-time |
| 500 엠버 | $2.99 | one-time |
| 1000 엠버 | $6.99 | one-time |
| 3000 엠버 | $19.99 | one-time |


## Frequently asked questions

### Is One Question Journal free?

One Question Journal is free to download, with no in-app purchases.

### Is Diffu free?

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

### Do One Question Journal or Diffu have ads?

Diffu shows ads; One Question Journal does not.

### Which is updated more often, One Question Journal or Diffu?

One Question Journal ships an update weekly, and Diffu every 2 weeks. Most recently, One Question Journal was updated on October 9, 2026 and Diffu on October 11, 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.*