Made for readers.

What Nimbus is

Nimbus is a calm, local-first ebook reader. It's built on a simple idea: the software should get out of the way so it's just you and the book. Beautiful typography, real focus, and none of the clutter. It's a product of Ninth Heaven, a small literary & arts studio.

Your books, your business

Everything happens on your device. You don't need an account to read, and your library never leaves your hands — not to us, not to anyone. This isn't a setting you switch on; it's how the whole thing is built.

• No account to read. Import a book and go. Your library, progress, highlights and notes live on your device.
• No ads. No tracking. No selling data. There's no advertising business here and never will be.
• Bring your own AI, free. If you use AI features with your own key, requests go straight to your provider — we never see them.

When you choose the cloud

Nimbus Plus adds optional, server-backed conveniences. They're never required, and here's exactly what they touch:

• Sync & backup stores your reading state — progress, highlights, bookmarks — so it follows you across devices. Book files stay on your device; only lightweight state syncs.
• Hosted AI sends only the passage you ask about to the model, to answer your question. Nothing else, and no training on your reading.
• Lifetime keeps everything on your own infrastructure — sync through your own iCloud or Dropbox, AI with your own key. Nothing routes through us at all.

You can export everything (highlights and notes to Markdown, in a tap) and leave any time. Local-first means you own your reading — full stop.