# Diffu vs Commaday

The clearest difference is device support: Diffu at 3 against Commaday's 1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Diffu sells 6 in-app purchases, starting at $2.99 per month and Commaday sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Diffu ships an update every 2 weeks, Commaday every 9 days. Both last shipped on November 5, 2026.

## The numbers

| Metric | Diffu | Commaday |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 2 weeks | **Every 9 days** |
| Monetization | — | Ad-supported |
| Size | 73 MB | 78 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [Jeong-Hwan Jang](https://appshunter.io/developer/1880755654) | [WonHyeong Chang](https://appshunter.io/developer/6791676100) |

## What reviewers say

### 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 |


### Commaday

[App page](https://appshunter.io/ios/app/commaday-one-line-journal/id6791676098)

This app helps you build a journaling habit by encouraging you to write just one sentence a day. It offers daily prompts and a unique 'comma' system to maintain streaks, even if you miss a day. Your entries are stored locally on your device for privacy.

**Highlights:** One-sentence daily entries, Daily themes and keywords, Streak tracking with 'commas', Calendar view of entries, Local device storage, Google Drive backup option

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium - All 3 Ways in one day | $9.99 | one-time |


## Frequently asked questions

### Is Diffu free?

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

### Is Commaday free?

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

### Do Diffu or Commaday have ads?

Both Diffu and Commaday show ads.

### Which is updated more often, Diffu or Commaday?

Diffu ships an update every 2 weeks, and Commaday every 9 days. Most recently, Diffu was updated on November 5, 2026 and Commaday on November 5, 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.*