A WordPress plugin for plotting some data in a custom field against time. It uses the Google charts API to render a simple line chart.
I use this plugin to keep a track of my weight. I have a private WordPress journal with a custom field called "Weight (kgs)" and each week when I make my journal entry I fill in my weight in this custom field. I have page called "My Weight" which is empty but uses the Fotherplot Template.
The plugin outputs a image and a list of the relevant data, example: