Catalyst vs HelixNotes

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.

HelixNotes is a private, open-source Markdown notes app. Your notes remain standard Markdown files under your control. No account is required, and HelixNotes has no company-operated cloud. Write with a clean visual editor or switch to source mode when you want direct access to the Markdown. Organize your work with notebooks, tags, wiki links and full-text search. Features include: • Tasks collected from checklists across your notes • List and calendar views with priorities and due dates • Wiki links and an interactive graph view • Daily notes with a built-in calendar • Markdown tables, code blocks and syntax highlighting • KaTeX mathematical notation and Mermaid diagrams • Outline navigation and tag autocomplete • Version history and automatic backups • Light, dark and customizable themes • Optional WebDAV sync with your own server • Optional AI tools using your own provider Nothing leaves your device unless you enable a feature that connects to an external service. Your notes stay readable outside HelixNotes, without a proprietary format or platform lock-in. HelixNotes is free software released under the GNU AGPLv3. Its source code is publicly available on GitLab.