An example plugin for Canvas for Pebble: https://play.google.com/store/apps/details?id=com.pennas.pebblecanvas

Available on Google Play @ https://play.google.com/store/apps/details?id=com.pennas.canvasnowplayingplugin

For more info on developing plugins, please see http://pebblecanvas.blogspot.co.uk/p/plugins.html