Someone posted a question about how to do this on the Day One Community site so I thought I’d build up a little iOS shortcut that:

– checks to see if you have an entry for today, if not it creates a blank one and then prompts you to choose a photo, resizes that photo and then appends the photo to today’s journal entry.

Here’s the shortcut, you’ll need to choose which journal to use and how large you want the inserted photo to be.