Those who have responsibility to plan lessons or support teachers in lesson planning in Mathematics and Science, you must take a deep look at http://www.goorulearning.org/
Gooru Learning is free and something I heard a great deal about at the Idaho Superintendents meeting earlier this week. To look deeply, ou must register (for free).
Amazing intellectual property and it is shareware–so free for your use and the taking. Are they on to something at Gooru Learning? If you have the chance, please let me know what you think!