Looks like every teacher should know about Gooru: it’s free – and free of adverts – with some big names in education behind it.
“A Search Engine for Learning
Teachers and students can use Gooru to search for rich collections of multimedia resources, digital textbooks, videos,
games and quizzes created by educators in the Gooru community.Gooru is free (of cost and ads) and developed by a 501(c)(3) non-profit organization whose mission is to honor the
human right to education.”
Try it out at http://goorulearning.org/, or find out more at http://about.goorulearning.org/