OpenCat vs Tampermonkey
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpenCat
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.
- 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
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Bring AI into every part of your workflow: chat, writing, translation, and search. · Multiple model options — local models, API Key, Cloud subscription, Apple Intelligence · MCP — supports MCP and tool calls · Web search — available on OpenCat Cloud and select providers · System-wide translation — select text in any app for instant AI translation · Content rendering — supports LaTeX formulas, Markdown, and code highlighting · Cross-platform — natively built for Mac, iPhone, and iPad · Data privacy — stored locally, synced across devices via iCloud [Pro Features] · AI Keyboard — invoke AI right in the text field of any app to polish or reply in one step · OpenCat Cloud subscription provides access to all major models [A Variety of Models] · OpenCat Cloud — fast access to leading models · Local models — one-tap download of open-source models for offline use, accelerated by Apple silicon · BYOK — use your own API Key, including Coding Plan · System models — supports Apple Foundation Models [OpenCat Cloud — Ready to Use, No Setup] · No sign-up, zero configuration, all major models supported · 50+ models — ChatGPT, Claude, Gemini, Grok, DeepSeek, GLM, MiniMax, Kimi, Qwen, Doubao, and more, all in one place · Online search supported [System-Level AI Translation] Set OpenCat as your default translation app to translate selected text directly in Safari, Mail, Notes, and any other app. Powered by large language models, translations are natural and fluent — far superior to traditional translation engines. [Local Models, Offline Inference] · One-tap download — popular open-source models like Llama, Qwen, and Gemma · Apple silicon acceleration — built on Apple's official MLX framework, fully leveraging GPU performance for fast, energy-efficient inference · Fully offline — works without internet, conversation data never leaves your device [Use Your Own API Key] · 25+ providers supported — OpenAI, Claude, Gemini, DeepSeek, Kimi, Qwen, Doubao, ERNIE, and more [Contact Us] Email: support@dreamoon.ai Terms of Use https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy & Third-party AI Service Privacy Policy https://opencat.app/privacy
Tampermonkey
Enhance and customize web pages with custom JavaScript programs. This tool allows users to easily create, manage, and run these scripts across all major browsers, adding new features or modifying existing ones on any website.
- Userscript management
- Web page customization
- JavaScript execution
- Cross-browser compatibility
- Script creation and editing
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Tampermonkey is a widely popular browser extension compatible with all major browsers. It lets you customize and enhance web pages using userscripts—small JavaScript programs that add or modify features. Easily create, manage, and run these scripts on any website with Tampermonkey.
Screenshots
Verdict
The clearest difference is price: OpenCat at Free against Tampermonkey's $2.99. OpenCat also leads on rating (4.6 vs 3.1) and update cadence (weekly vs every 5 months). Tampermonkey's advantage is in-app purchases (none vs 4) and chart position (#17 vs unranked). On review sentiment, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
OpenCat is free to download; Tampermonkey costs $2.99 up front. OpenCat sells 4 in-app purchases, starting at $3.99 per month. Tampermonkey asks for nothing beyond the download.
OpenCat holds the better App Store score, 4.6 against 3.1. That said, the two scores are not equally well evidenced: OpenCat has 852 ratings behind it against 61, so its average is the more settled of the two. Written reviews point the same way: 65% of OpenCat's written reviews are positive against 58% of Tampermonkey's.
OpenCat ships an update weekly, Tampermonkey every 5 months. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.
| Parameter | OpenCat | Tampermonkey |
|---|---|---|
| Price | Free — better | $2.99 |
| Rating | 4.6 (852 ratings) — better | 3.1 (61 ratings) |
| Positive reviews | 64.6% of reviews — better | 57.5% of reviews |
| Number of ratings | 852 — better | 61 |
| Update frequency | Weekly — better | Every 5 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Best chart rank | — | #17 — better |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 17.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 96 MB | 7 MB |
| Age rating | 17+ | 4+ |
| Developer | Early Moon, LLC | Jan Biniok |
Customer experience
OpenCat
Tampermonkey
User reviews
OpenCat
From 852 App Store ratingsWhat we love
- 🚀 Fast and responsive
- 👍 Convenient and user-friendly
- 💡 Customizable API integrations
- 🌐 Syncs across devices
- 🎨 Clean and visually appealing design
Room to improve
- 🐛 Bugs and performance issues
- 🔒 Lack of custom API support
- 💻 Compatibility issues with older devices/OSes
- 🗂️ Difficulty managing conversations
- 📤 Inability to export chat data
Tampermonkey
From 61 App Store ratingsWhat we love
- 🚀 Well executed
- 👍 Essential plugin/extension for all browsers
- 💡 Sync userscripts across browsers
- 👍 Needed this
- 👍 Good
Room to improve
- 🐛 Bug on iPad
- 🐛 Glitching on iPad
- 🐛 Unable to install scripts
- 🐛 Unusable on iPadOS
- 🐛 No response on iPad
Bugs and requests
OpenCat
Reported bugs
6 issues- Streaming response disruptions
- Disappearing API key input fields
- Inconsistent Markdown rendering
- Keyboard extension not working as expected
- Sync issues between devices
Show 1 moreShow fewer
- Crashes and freezes when handling large inputs
Requested features
7 requests- 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
Show 2 moreShow fewer
- Prompt library and sharing functionality
- Integration with other productivity apps (e.g., Shortcuts)
Tampermonkey
Reported bugs
4 issues- Plugins cannot be installed properly
- Screen continuously flickers
- Not usable in Chrome
- Features not working as expected
Requested features
2 requests- Set cookie feature
- Dark mode option
In-app purchases
OpenCat
- Cloud AI3 Days trial$3.991 Month
- Cloud AI$24.991 Year
- Tokens Package$5.99
- OpenCat Pro$9.99
Tampermonkey
No in-app purchases









