# 21DaysOfChange vs Dayletter

The clearest difference is in-app purchases: Dayletter at none against 21DaysOfChange's 4. Dayletter also leads on update cadence (every 3 days vs every 9 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. 21DaysOfChange sells 4 in-app purchases, starting at $4.99 per month. Dayletter asks for nothing beyond the download.

21DaysOfChange ships an update every 9 months, Dayletter every 3 days. The most recent releases landed on October 21, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | 21DaysOfChange | Dayletter |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/dayletter/id6800344958/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 3 days** |
| Monetization | — | Free |
| Size | 59 MB | 4 MB |
| Requires iOS | **16.4** | 17.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Hong Son Vu](https://appshunter.io/developer/1767993431) | [磊 徐](https://appshunter.io/developer/6798090893) |

## What reviewers say

### 21DaysOfChange

[App page](https://appshunter.io/ios/app/21daysofchange/id6677019535)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 21DaysOfChange Monthly Premium | $4.99 | per month |
| 21DaysOfChange Monthly Business | $12.99 | per month |
| 21DaysOfChange Yearly Premium | $34.99 | per year |
| 21DaysOfChange Yearly Business | $89.99 | per year |


### Dayletter

[App page](https://appshunter.io/ios/app/dayletter/id6800344958)

This private journal app creates dated Markdown entries in your chosen Obsidian folder. It safely merges new content with existing files and allows categorization by type, such as investing or exercise. Capture moments, manage tasks with due dates, and access your journal locally without accounts or ads.

**Highlights:** Obsidian-compatible Markdown and tags, Dated Markdown entry creation, Safe merging with existing files, Categorization by type (investing, exercise, etc.), Task management with start and due dates, Local drafts and iCloud Drive support, No accounts, ads, or data uploads

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

**In-app purchases:** none


## Frequently asked questions

### Is 21DaysOfChange free?

21DaysOfChange is free to download, with in-app purchases available.

### Is Dayletter free?

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

### Do 21DaysOfChange or Dayletter have ads?

Neither 21DaysOfChange nor Dayletter shows ads.

### Which is updated more often, 21DaysOfChange or Dayletter?

21DaysOfChange ships an update every 9 months, and Dayletter every 3 days. Most recently, 21DaysOfChange was updated on October 21, 2026 and Dayletter 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.*