# iMark · Image Annotation Tool vs OpenCat

The clearest difference is update cadence: OpenCat at weekly against iMark · Image Annotation Tool's every 2 months. iMark · Image Annotation Tool's advantage is iOS requirement (13.0 vs 17.0). On price, rating, review sentiment and ratings volume there is nothing between them.

Both are free to download. iMark · Image Annotation Tool sells 4 one-off in-app purchases and OpenCat sells 4 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

On the App Store both sit at effectively the same score — 4.6 for iMark · Image Annotation Tool against 4.6 for OpenCat. Both are backed by a comparable volume of ratings — 384 and 855 respectively. Written reviews are what separate them: 72% of iMark · Image Annotation Tool's written reviews are positive against 65% of OpenCat's.

iMark · Image Annotation Tool ships an update every 2 months, OpenCat weekly. The most recent releases landed on November 2, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | iMark · Image Annotation Tool | OpenCat |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (384 ratings)](https://appshunter.io/ios/app/imark-image-annotation-tool/id1174741369/reviews)** | [4.6 (855 ratings)](https://appshunter.io/ios/app/opencat-ai-chat-agent-mcp/id6445999201/reviews) |
| Number of ratings | 384 | **855** |
| Positive reviews | **71.7% of reviews** | 64.6% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 93 MB | 96 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 17+ |
| Developer | [iDaily Corp.](https://appshunter.io/developer/364264742) | [Early Moon, LLC](https://appshunter.io/developer/1119881923) |

## What reviewers say

### iMark · Image Annotation Tool

[App page](https://appshunter.io/ios/app/imark-image-annotation-tool/id1174741369)

Enhance and annotate images with a comprehensive set of tools. Import from your photo library, camera, or maps, and customize your markups with various styles. Easily export and share your creations.

**Highlights:** Diverse annotation tools (arrow, text, mosaic, etc.), Import from photo library, camera, and maps, Customizable color schemes and history sessions, Crop and layer management, Export with custom image size, Supports iOS Photo Extension

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Coffee | $2.99 | one-time |
| Silver Coin | $5.99 | one-time |
| Gold Coin | $14.99 | one-time |
| Coffee for Everyone | $29.99 | one-time |

**What reviewers like**

- 👍 Intuitive and easy-to-use interface
- 🎨 Comprehensive annotation tools (arrows, shapes, text, magnifier)
- 💰 Completely free with no ads
- 🎯 Powerful features for screenshot markup
- 🔧 Customizable colors and styling options

**What reviewers complain about**

- 💧 Persistent watermark on all saved images
- 🌐 Language defaults to Chinese with difficult switching
- 📝 Text size limitations on large images
- 🎨 Limited font customization options
- ⚙️ Text bubble tail control is limited

**Reported bugs**

- App crashes when using brush/pen features
- Export button hidden by system UI
- Annotations disappearing after one day
- Keyboard engagement obscures image during text input
- Magnifier tool functionality issues

**Requested features**

- Ability to remove watermark (paid option requested)
- Multiple language support with easy switching
- Filled/solid geometric shapes
- Curved arrows instead of straight only
- Multiple font selection from Google Fonts


### OpenCat

[App page](https://appshunter.io/ios/app/opencat-ai-chat-agent-mcp/id6445999201)

This AI utility tool offers seamless integration of advanced AI models into your daily routine on Mac, iPhone, and iPad. It features a user-friendly interface, keyboard extensions for in-app AI access, and Siri/shortcut integration for automation. Supports a wide range of popular AI models and offers team deployment options.

**Highlights:** Support for latest popular AI models, Keyboard extensions for in-app AI, Realistic voice synthesis, Siri and shortcut integration, Team deployment with Docker, Customizable AI parameters, Markdown content rendering

**Features:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cloud AI | $3.99 | per month |
| Cloud AI | $24.99 | per year |
| Tokens Package | $5.99 | one-time |
| OpenCat Pro | $9.99 | one-time |

**What reviewers like**

- 🚀 Fast and responsive
- 👍 Convenient and user-friendly
- 💡 Customizable API integrations
- 🌐 Syncs across devices
- 🎨 Clean and visually appealing design

**What reviewers complain about**

- 🐛 Bugs and performance issues
- 🔒 Lack of custom API support
- 💻 Compatibility issues with older devices/OSes
- 🗂️ Difficulty managing conversations
- 📤 Inability to export chat data

**Reported bugs**

- Streaming response disruptions
- Disappearing API key input fields
- Inconsistent Markdown rendering
- Keyboard extension not working as expected
- Sync issues between devices

**Requested features**

- Support for more AI models (e.g., Ollama, Groq)
- Markdown rendering for chat responses
- Ability to upload images and files
- Customizable keyboard extensions
- Background task support for long-running queries


## Frequently asked questions

### Is iMark · Image Annotation Tool free?

iMark · Image Annotation Tool is free to download, with in-app purchases available.

### Is OpenCat free?

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

### Which has better reviews, iMark · Image Annotation Tool or OpenCat?

iMark · Image Annotation Tool is rated higher. iMark · Image Annotation Tool averages 4.6 out of 5 from 384 ratings, while OpenCat averages 4.6 from 855 ratings.

### Do iMark · Image Annotation Tool or OpenCat have ads?

Neither iMark · Image Annotation Tool nor OpenCat shows ads.

### Which is updated more often, iMark · Image Annotation Tool or OpenCat?

iMark · Image Annotation Tool ships an update every 2 months, and OpenCat weekly. Most recently, iMark · Image Annotation Tool was updated on November 2, 2026 and OpenCat on November 7, 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.*