Callisto Bound makes focused, native apps for Mac, iPhone and iPad — fast to use, built on open formats, and respectful of your data.
Our apps
Each Callisto Bound app does one job well, feels at home on Apple platforms, and keeps your work in formats you own.
Mac · iPhone · iPad
A fast, focused Markdown notes app. Your notes are plain files you own — keep them in Ursa, in a folder on your Mac, or in Dropbox synced to your iPhone and iPad — and they work alongside apps like Obsidian.
We’re building more productivity apps for Apple platforms. Ursa Notes is the first.
About Callisto Bound
Callisto Bound LLC is an independent software company. We design and publish productivity apps for Apple platforms, guided by a few simple principles.
Your work lives on your devices and in storage you choose — never on our servers. We don’t sell data or show ads.
Built for Mac, iPhone and iPad with the look, speed and keyboard shortcuts you expect.
Plain files that open anywhere. No lock-in: your work outlasts any app, including ours.
Questions, feedback or press: we’d love to hear from you.