# IsleMark vs Cat Letter

The clearest difference is price: Cat Letter at Free against IsleMark's $1.99. Cat Letter also leads on update cadence (every 5 days vs every 2 weeks). IsleMark's advantage is in-app purchases (none vs 5). On ads, device support and iOS requirement there is nothing between them.

Cat Letter is free to download; IsleMark costs $1.99 up front. Cat Letter sells 5 one-off in-app purchases. IsleMark asks for nothing beyond the download.

IsleMark ships an update every 2 weeks, Cat Letter every 5 days. Both last shipped on October 25, 2026.

## The numbers

| Metric | IsleMark | Cat Letter |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[4.8 (6 ratings)](https://appshunter.io/ios/app/islemark/id6621264654/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 88.9% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 5 days** |
| Monetization | Paid | — |
| Size | 72 MB | 8 MB |
| Requires iOS | 17.0 | **16.0** |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Pop Up Limited](https://appshunter.io/developer/1808148664) | [LONG VOYAGE TECHNOLOGIES PTE. LTD.](https://appshunter.io/developer/1896372290) |

## What reviewers say

### IsleMark

[App page](https://appshunter.io/ios/app/islemark/id6621264654)

Customize your device's dynamic island with text, emojis, and decorative patterns. This app also serves as a convenient memo tool to help you remember tasks.

**Highlights:** Dynamic island text input, Emoji support, Upload decorative patterns, Minimized and expanded view customization, Memo tool for tasks

**Features:** Vision Pro support

**In-app purchases:** none


### Cat Letter

[App page](https://appshunter.io/ios/app/cat-letter/id6773315989)

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Rainy Post | $0.99 | one-time |
| Mid-Autumn Post | $1.99 | one-time |
| Halloween Post · Little Witch | $2.99 | one-time |
| Summer Fireworks Festival | $2.99 | one-time |
| Mantou's Christmas Mail Night | $2.99 | one-time |


## Frequently asked questions

### Is IsleMark free?

IsleMark costs $1.99, with no in-app purchases.

### Is Cat Letter free?

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

### Do IsleMark or Cat Letter have ads?

Neither IsleMark nor Cat Letter shows ads.

### Which is updated more often, IsleMark or Cat Letter?

IsleMark ships an update every 2 weeks, and Cat Letter every 5 days. Most recently, IsleMark was updated on October 25, 2026 and Cat Letter 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.*