I have used Day One for journalling across my Mac, iPhone and iPad for many years--it's an elegant solution that makes it incredibly easy to keep on top of multimedia journal entries.
Sometimes, it's nice to publish those journal entries, ideally without loosing any of the extra information (such as location, weather, etc). To make this easy, I wrote day-one-to-markdown, a command-line utility that converts Day One's JSON exports to a Jekyll-friendly directory of Markdown (with Front Matter), and multimedia files. Since all metadata is added to the Front Matter, it's really easy to handle in your site templates.
You can learn more from the project page on GitHub.