This script converts JSON file from Simplenote Export web service into individual Markdown files.
It's nothing fancy, first argument is the JSON file, second argument is directory to write the notes to. The note files are named by using the first 60 characters (or a little more, up to a full word) of the first line of the note, stripped of any characters outside of letters, simple dash, underscore, brackets, space, single quote, and plug and equal signs.
Tags are stored on the bottom of the note on a line starting with "TAGS:", and the SimpleNote note ID/key as a "KEY:" line.