> For the complete documentation index, see [llms.txt](https://sigma-1.gitbook.io/notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sigma-1.gitbook.io/notes/prototyping.md).

# Prototyping

## GUI

* [OmniGraffle](https://www.omnigroup.com/omnigraffle)