Nyth AI vs Catalyst
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Nyth AI
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Nyth AI: private AI chat on your iPhone and iPad Use capable AI without sending your chats to our servers. Nyth runs language models on your device so your conversation text stays local. No account required. Built for people who care about privacy. BRAINS FOR DIFFERENT JOBS Choose the model that fits you, or start from Home with a preset and we will route you to the best brain for that flow: • Flash: Fast answers for quick questions (~300 MB) • Nova: General chat and creative brainstorming (~1 GB) • Sage: Code, math, and deeper analysis (~1.5 GB) • Spark: Apple's on-device AI on supported iPhones and iPads. No download. Instant start. (iPhone 15 Pro and later with Apple Intelligence) • Apex: Our most capable on-device brain. Stronger reasoning, code, and analysis (~2.5 GB). Included with Nyth Pro. Switch brains anytime in the Brains tab. SMART HOME PRESETS Code, research, creative writing, business, homework, and more. Each preset is tuned to pick a strong brain for the task. NATURAL VOICE • Dictate with the microphone (on-device speech recognition when supported) • Hear replies with spoken output; we clean up markdown so it sounds more natural • Simple recording and playback controls NYTH PRO (ONE-TIME PURCHASE) Upgrade once to unlock: • Apex: Phi-3.5 Mini, our smartest downloadable brain • iCloud Backup: Sync conversations across your iPhone and iPad via your own iCloud (optional; uses your Apple ID storage, not our servers) • Search: Find anything across your saved chats • Export: Share or save conversations as readable text • Custom Personas: Create your own AI personalities with custom instructions Free tier includes Flash, Nova, Sage, Spark (when eligible), voice I/O, Home presets, and unlimited local chat. PRIVACY-FIRST • AI inference on your device after you download a model (Spark uses Apple's built-in model with no download) • We do not run your chat on our servers • No ad or cross-app tracking in the app • Chats are stored on your device; optional iCloud backup stays in your private iCloud container BEFORE YOU CHAT Downloading a brain is a one-time fetch over Wi-Fi (typically hundreds of MB up to ~2.5 GB for Apex) from Hugging Face. After that, chat works offline with the models you have installed. WHO IT IS FOR Professionals, students, writers, and developers who want capable AI without shipping every message to the cloud. Nyth AI: local inference. Your data on your device.
Catalyst
Access multiple leading AI models in one app, compare their responses, and generate images or videos. It also supports Python code execution and web searches with sources. Bring your own API keys for flexibility and control over your data.
- Access multiple AI models
- Compare AI model responses
- Generate images and video clips
- Secure Python sandbox
- Web search with sources
- Attach files and photos
- Persistent conversation memory
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Catalyst puts today's best AI models in one place — and lets you switch between them with a tap. Chat with models from Anthropic, OpenAI, Google, and more in a single conversation, and bring your own API keys so you're never locked in. WHAT YOU CAN DO • Chat with multiple AI models — pick the right one for each question, or compare answers side by side • Generate images from a prompt, and create or animate short video clips • Run Python in a secure sandbox for calculations, data analysis, and charts • Search the web for current information, with sources • Attach photos and files and ask about them • Give the assistant a memory that carries useful context across conversations BRING YOUR OWN MODELS Catalyst is model-agnostic. Connect your own provider keys — Anthropic, OpenAI, Google, or any OpenAI-compatible endpoint — and use the models you choose at the provider's own rates. A better, cheaper model ships every few weeks; point Catalyst at whatever's best today. YOUR DATA, YOUR CONTROL Your conversations sync securely so your history follows you across devices. Export everything you've created at any time, and delete individual chats — or your whole account — from inside the app. Catalyst on iPhone and iPad is the companion to the full workspace at catalyst.voov.ai, where you can also build workflows, mini apps, and connect data sources. Sign in with Apple, Google, or email.
Screenshots
Verdict
The clearest difference is in-app purchases: Catalyst at none against Nyth AI's 1. Catalyst also leads on update cadence (every 9 days vs every 6 weeks). On price, ads, device support and iOS requirement 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
Both are free to download. Nyth AI sells 1 one-off in-app purchase. Catalyst asks for nothing beyond the download.
Nyth AI ships an update every 6 weeks, Catalyst every 9 days. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.
| Parameter | Nyth AI | Catalyst |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 6 weeks | Every 9 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | — | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.6 | 18.0 — better |
| Further details — not scored | ||
| Size | 28 MB | 31 MB |
| Age rating | 9+ | 12+ |
| Developer | ImmiGrader Tech LLC | ObjectGraph LLC |
In-app purchases
Nyth AI
- Nyth AI Pro$5.99
Catalyst
No in-app purchases









